The use of investigative genetic genealogy (“IGG”) as a basis for arresting suspects in complex and dormant investigations is raising serious concerns about whether the due process rights of criminal defendants in these cases are being violated. This Note provides a comprehensive look at the role of this groundbreaking, yet little-understood technology in criminal prosecutions. Technological advances have historically necessitated that courts expand and reinterpret legal principles. As a novel derivative of traditional DNA testing, this Note argues IGG should similarly require that discovery statutes be amended or rewritten to adapt to this cutting-edge technique, which is so new that it lacks uniform standards and certifications. By comparing IGG to traditional DNA profiling and other forensic evidence, this Note reveals the reliability and privacy issues arising from such an unconventional application of established scientific practices. While DNA evidence is now considered the “gold standard” and has attained an “aura of infallibility” in the criminal justice system, highly regarded scientific techniques have later been discredited, resulting in numerous wrongful convictions.
There are early warning signs with respect to IGG, which have already led to false identifications, underscoring the need to subject it to the scrutiny of the discovery process. It is crucial to strike a reasonable balance that protects privacy interests but enables defendants to mount a vigorous defense by requiring the disclosure of material to challenge the admissibility of IGG, effectively cross-examine witnesses, and collect potentially exculpatory information. This Note delineates the specific language and scope of potential amendments or reinterpretation of discovery statutes needed to prevent prosecutors from having an unfair advantage and ensure that suspects obtain fair trials.
Introduction
Investigative genetic genealogy (“IGG”) is being heralded as a breakthrough forensic technique to solve decades-old cold cases and complex investigations with few leads.1 Since its first use in 2018, this technology has led to the convictions of more than 500 people accused of rape and murder.2 IGG combines genomics, genealogy, and “computer database technologies” to identify sources of unknown crime scene DNA.3 Investigators upload DNA profiles to public databases of direct-to-consumer testing services, creating family trees to help zero in on suspects.4 IGG has resolved many dormant cases, as well as active criminal investigations that lacked direct evidence to implicate suspects,5 such as the 2022 murders of four University of Idaho students.6 One question remains: how much information must be turned over to the defense as part of discovery to enable challenges to the admissibility and reliability of the evidence?
Historically, technological advances have required courts to expand and reinterpret legal principles.7 Since IGG is using DNA in a novel way,8 this technology necessitates amending or interpreting discovery statutes to account for the implications of this scientific advancement. To find DNA matches, traditional investigations employ the Combined DNA Index System (CODIS), which contains offender DNA information derived from noncoding regions of the genome.9 IGG is different. Law enforcement enters crime scene DNA into direct-to-consumer genetic databases, which obtain DNA from individuals seeking to learn about their ancestry or medical risks.10 These databases use DNA from other genomic regions, finding mutations that facilitate identification of family members.11 Newer, more sensitive sequencing methods can create DNA profiles from small, mixed, or degraded samples.12
As a derivative of traditional DNA testing technology,13 which has attained an “aura of infallibility” in the criminal justice system,14 it is crucial for the defense to have access to IGG materials.15 DNA is treated with “an extraordinary, and even absolute, degree of certainty.”16 A Gallup poll revealed that eight in ten Americans perceive DNA as “completely” or “very” reliable.17 In a survey of former jurors and college students, virtually all participants called DNA “the most accurate” form of forensic evidence.18 The mere presence of forensic evidence was enough for a conviction, even if additional evidence indicated the defendant was not guilty, according to forty percent of respondents of another survey.19 How persuasive is DNA in criminal trials? Consider the results of a 2021 study that asked participants to read seven “vignettes depicting a crime.”20 In a murder case, the odds of a guilty verdict were three times greater when DNA evidence was introduced.21 In a rape case, the odds were twenty times greater.22 People not only trust DNA evidence, but many expect it to be presented at trial.23
Although DNA evidence is now considered the “gold standard,”24 circumspection should persist. Other scientific techniques once deemed reliable and used to convict a multitude of defendants have been discredited.25 The National Registry of Exonerations found that, as of September 2024, 1,030 out of 3,591, or nearly one in three, wrongful convictions were based on false or misleading forensic evidence, ranging from bitemarks to blood spatter.26 Not only did the pediatrician who first advanced the shaken baby syndrome (“SBS”) theory eventually acknowledge “the science is faulty,”27 a New Jersey appellate court called SBS “junk science.”28
Moreover, traditional DNA testing supplanted fingerprint analysis as the strongest available forensic evidence because it involved less interpretation and bias.29 IGG should therefore be of particular concern because it requires more human evaluation than standard DNA profiling.30 Questions are already being raised regarding IGG’s reliability.31 The use of deteriorated crime scene samples, which frequently contain DNA from multiple contributors, can impact the validity of resulting IGG identifications.32 In addition, there are no uniform standards or certifications governing IGG equipment or genealogists.33 IGG has led law enforcement to falsely identify criminal suspects in several cases.34 Since DNA data obtained through IGG is powerful evidence linking a defendant to a crime, information regarding this novel technique must be provided during discovery so an adequate defense can be prepared.35
Existing discovery statutes should be amended or interpreted to include cases where law enforcement uses IGG to identify and prosecute a criminal defendant. Notwithstanding that these databases could implicate large numbers of people,36 it is important to strike a reasonable balance between the privacy interests of relatives identified by family trees and the ability of suspects to mount vigorous defenses. The defense needs to be provided with sufficient information to effectively cross-examine witnesses, including analysts and genealogists who obtained and interpreted IGG data.37 In addition, ample material must be turned over to enable the defense to challenge the admissibility of IGG as scientifically unreliable and uncover potentially exculpatory information, such as alternative suspects.38 While there should be an option for prosecutors to obtain protective orders to shield the identities of individuals in family trees, they should only be issued in limited circumstances.39 Undoubtedly, this technology can be an effective law enforcement tool, but it must be used responsibly. Given the lofty status of DNA,40 leaving decisions as to the relevance and materiality of IGG information in the sole discretion of prosecutors gives them an unfair advantage. Therefore, the defense should be provided with adequate discovery to challenge IGG evidence. With technology constantly changing and improving, the law must adapt.41
In cases where IGG is used by law enforcement to charge an individual with a crime, the prosecution, pursuant to its discovery obligations, must be required to turn over to the defense all IGG-related materials that led law enforcement to identify and prosecute the defendant.42 As such, discovery statutes should be amended or interpreted to include IGG because (1) family tree information uncovered as part of the IGG process was used by law enforcement as the basis to identify a suspect; (2) this data will permit the defense to acquire potentially exculpatory information, effectively cross-examine those who obtained and analyzed the IGG data, and raise challenges to IGG’s reliability and scientific acceptance; and (3) criminal defendants, under the Sixth Amendment, have the right to access all evidence relevant to their cases.43
This Note is divided into three parts. Part I explores the cutting-edge IGG process and the reliability and privacy concerns presented by using this investigative technique in criminal cases, comparing it to traditional DNA profiling and other forensic evidence.44 Part I further explains pretrial discovery and delves into existing case law regarding whether the defense should be given access to IGG materials.45 Part II discusses the need for amending or interpreting existing discovery statutes to provide the defense with access to IGG information.46 Part III delineates the specific language and scope of proposed amendments or interpretations of discovery statutes to ensure that criminal defendants’ due process rights are protected.47
I. Background
A. What Is Investigative Genetic Genealogy (“IGG”)?
1. How Does IGG Work?
To understand IGG and how it differs from standard DNA testing, it is necessary to understand law enforcement procedures related to DNA evidence. Typically, when a crime scene sample, such as blood or semen, is collected, investigators first generate a short tandem repeat (“STR”) profile, the most commonly used method to profile DNA in criminal cases.48 To identify a suspect, the STR profile is entered into CODIS to see if there is a match to the millions of existing profiles.49 If there is a match, the suspect’s name is provided to investigators.50 Otherwise, police revert to routine investigatory practices, such as interviewing witnesses and gathering additional evidence.51 Should these methods fail to result in an arrest, a complex process known as IGG is a new resource.52 Law enforcement sends the crime scene sample to a private laboratory to conduct a different type of DNA profiling that converts the sample into a single nucleotide polymorphism (“SNP”), which is useful in differentiating genetic lineages.53
As an SNP, the sample is uploaded to one or more consumer genetic databases.54 GEDmatch, FamilyTreeDNA, and DNASolves are the only companies that permit police to upload SNPs belonging to unknown perpetrators.55 These databases generate potential matches based on “the amount and length of shared DNA.”56 Once matches are located, genealogists determine whether IGG will be useful.57 Generally, if at least one match locates a second or third cousin, genealogists will move forward and construct family trees.58
Family trees are created by locating “a common ancestral couple for all people in the cluster.”59 Genealogists then conduct descendancy research to find “candidates of interest,”60 determining relatedness of potential family members through “overlapping genetic regions.”61 Birth, voting, and census records, as well as obituaries, newspapers, and social media websites are also used to construct family trees.62 IGG can work with more distant matches, but targeted testing is required,63 which involves police requesting that potential relatives take a commercial genetic genealogy test and enter their results to the specific database being used to verify “that the correct branch of the family tree is being researched.”64
From the family tree, genealogists provide law enforcement with a candidate list, which becomes “an investigative tool.”65 Before an arrest can be made, police must collect a candidate’s DNA and compare it to the crime scene sample.66 Investigators frequently retrieve this DNA from a discarded item.67 If there is a match, they are then required to obtain a warrant to swab the suspect’s mouth for DNA.68 Only when the suspect’s DNA matches the crime scene DNA may police make an arrest.69
2. Reliability and Privacy Concerns Associated with IGG
Despite IGG’s potential value to law enforcement as an investigative tool, significant questions have been raised about its reliability and impact on privacy rights.70 First, SNPs are comparatively more revealing than STRs, raising serious privacy concerns.71 In a standard criminal case, forensic technicians analyze crime scene DNA using STR testing.72 STRs are noncoding regions of the genome unique to every individual and are often considered “junk” DNA, meaning they do not contain any information about “genetic disease or predispositions.”73 Conversely, SNPs include parts of the genome that are more revealing, particularly information about the propensity for contracting diseases or displaying particular traits.74 Law enforcement only receives the same limited information provided to regular customers, which does not include SNP profiles of potential relatives.75 However, any user, including investigators, can upload them to chromosome browsers that reveal portions of the DNA shared with other database participants.76 Since SNPs can provide information about an individual’s “appearance[] [and] health risks,” the private data revealed is ripe for misuse by police.77
Furthermore, crime scene samples from which SNPs are created are imperfect.78 They are often low quantity and quality and require analyst interpretation.79 The DNA’s source is key to how much analysis is needed.80 Single-source samples and simple mixtures, defined as samples containing DNA from two contributors in equal amounts, one of which is known, require little interpretation and are the most precise.81 However, other types of DNA samples, including touch DNA deposited when a person comes in contact with an object,82 and complex mixtures containing DNA from more than two sources, are more reliant on subjective opinions of examiners.83 Crime scene samples are frequently complex mixtures, making it difficult for analysts to obtain the single profiles necessary for IGG.84 Accordingly, the suspect profile developed from the mixture may generate false positive or negative results.85 One study reported that forty percent of the SNPs tested were false positives;86 another concluded that SNPs do not accurately “genotype[e] very rare variants.”87 Significantly, SNPs are more susceptible to error than STRs.88
Likewise, the IGG process itself is imperfect. Genealogists can only limit candidates “to the offspring of a specific couple” and cannot differentiate between siblings.89 Moreover, candidate lists have previously led law enforcement astray, resulting in the investigation and arrest of the wrong people.90 During the Golden State Killer investigation, which was the first case to use IGG to capture a serial killer who terrorized California from 1976 to 1981,91 police misidentified the suspect twice.92 Both men were found to be innocent after comparing their DNA to the crime scene sample.93 In addition, another innocent man, Michael Usry, was wrongfully identified in an Idaho cold case after he was deemed a potential suspect through IGG.94 Usry’s film Murderabilia raised investigators’ suspicions even further, leading to his arrest.95 However, he too was eventually cleared after submitting a DNA sample.96
Unlike most other scientific disciplines, IGG lacks standards and certifications.97 Oversight structures are nonexistent for the SNP testing technology, equipment, and laboratories.98 No qualifications or trainings are necessary for genealogists, many of whom are “hobbyists turn[ed] professional[s].”99 Thus, genealogists have no uniform rules and regulations.100 In addition, direct-to-consumer genealogy companies keep their methodologies secret and consider them proprietary.101 Therefore, the methodologies have not undergone peer review.102 Since the procedures vary between companies, their results can differ.103
3. IGG Compared to Other Forensic Evidence and Technology
The concerns about IGG can be compared to other types of scientific evidence once considered reliable to obtain criminal convictions but later deemed questionable.104 One example is bloodstain pattern analysis (“BPA”), first used to convict a criminal defendant in 1954.105 BPA’s use by law enforcement became widespread after the 1971 publication of a report affirming BPA’s scientific precision.106 Decades later, in 2009, the National Academy of Sciences (NAS) released a report raising doubts about BPA’s accuracy and reliability, revealing foundational issues, as well as the variability and subjectivity inherent in the analysis.107 An 11.2% error rate was discovered among BPA analysts, who had difficulty reproducing results.108 As such, courts have repeatedly raised issues as to its admissibility.109 The United States District Court for the District of New Mexico noted the absence of scientific precision in BPA and the inability to verify the science’s accuracy.110 The New York Court of Appeals found BPA questionable, cautioning against admitting it into evidence.111 Moreover, even before the NAS report, courts were hesitant to admit BPA. In 1987, an Illinois appellate court held that the prosecution’s failure to establish BPA’s scientific reliability, which was used to convict a criminal defendant, was reversible error.112 Likewise, in 2000, the Texas Court of Appeals questioned BPA’s scientific validity and found the evidence to be “dangerously misleading.”113
Another forensic science of dubious reliability is bitemark evidence, which law enforcement began using in the 1970s.114 A 2009 NAS report revealed the inaccuracy of this evidence, finding significant error rates,115 including high numbers of false positives and varying results among analysts.116 The report noted that there is no scientific foundation for bitemark evidence,117 pointing out the skin’s ability to “change over time and . . . be[come] distorted,” which reduces the evidence’s validity,118 as well as the lack of scientific support for the uniqueness of human dentition.119 Moreover, the National Institute of Standards and Technology recently released a report concluding that bitemark evidence lacks adequate scientific foundation.120 It cited the absence of research establishing bitemark uniqueness and highlighted issues with bitemarks themselves, including “intra-individual variation” and the inaccuracy of background studies.121 Courts have begun addressing its unreliability.122 In granting a new trial for a convicted criminal defendant,123 a Georgia trial court ruled that bitemark evidence is “inherently unreliable”124 and “unsupported by science.”125 In addition, the Texas Court of Criminal Appeals held that inaccurate bitemark evidence led to the wrongful conviction of a defendant.126 The court concluded that there was no scientific support for the uniqueness of bitemarks and determined that the available scientific research discredited this type of evidence.127
The impact of permitting the use of dubious scientific techniques and theories can have far-reaching and devastating consequences.128 For example, the science behind SBS, which was used to convict approximately 1,431 people between 2008 and 2018, has been deemed erroneous and illegitimate.129 The biggest issue is the lack of agreement among scientists for what constitutes SBS, leading to variable application of the science in courts.130 What scientists believed to be symptoms of SBS in the brain, such as hemorrhaging and swelling,131 can also be caused by medical issues other than abuse, including short falls and lack of oxygen to the brain.132 Indeed, the science behind SBS has never been proven.133 The SBS hypothesis is so questionable that many states have overturned convictions based on the theory.134 An Illinois district court called it “more of an article of faith than a proposition of science.”135 The Court of Appeals of Wisconsin and the Massachusetts Supreme Judicial Court both found that if the change in the scientific understanding of SBS was presented to reasonable juries, they would not find the two respective defendants guilty, and ordered new trials.136 Moreover, a New Jersey appellate court found SBS “scientifically unreliable” since the science behind it “has never been proven” and disagreement among scientists remains as to the symptoms of SBS.137
Due to the foundational issues associated with what was once considered probative forensic evidence, courts are questioning the admissibility of certain scientific disciplines.138 This development supports the argument that the defense should have access to all IGG-related materials. Ultimately, IGG is a new, relatively untested, scientific technique that may not withstand further scrutiny.139 Without reviewing the IGG work product, there is no way for the defense to raise potential issues regarding its admissibility and properly cross-examine genealogists and other experts or participants in the IGG process.
B. Discovery
1. Background
Pretrial discovery, which is codified by statute, sets forth the obligations of the prosecution and defense to exchange information prior to trial.140 To avert “trial by ambush,” the prosecution is required to turn over information and witnesses it plans to use as evidence, as well as exculpatory material under Brady v. Maryland.141 Discovery ensures defendants receive a fair trial,142 as guaranteed by the Sixth Amendment,143 by providing them with the means to challenge the reliability of the evidence.144 If defendants are not given “access to the raw materials integral to the building of an effective defense,”145 prosecutors can be sanctioned and a new trial may be warranted.146 Raw materials include written reports, witnesses who may be called to testify, and any potentially exculpatory information.147
2. Scientific Evidence and Discovery
Typically, discovery statutes mandate that scientific reports, including “medical and physical examinations, scientific tests, and experiments,” must be turned over to the defense.148 However, some states limit the discoverable scientific reports to those that will be introduced by the prosecution at trial.149 With respect to the discoverability of police reports, there is more variation between jurisdictions, with only a few states requiring that all police reports automatically be provided to the defense during discovery.150 In 2007, the American Bar Association (ABA) published standards for pretrial discovery related to DNA evidence, which recommended that prosecutors be required to turn over lab reports, case notes, raw electronic data, and exculpatory material “within a specified and reasonable time prior to trial.”151 The NAS was so concerned about defendants’ access to DNA evidence that it concluded in its 1992 report that prosecutors must be required to provide the defense with “[a]ll data and laboratory records” regarding DNA.152
However, the interpretation of discovery statutes becomes more complex when considering whether the prosecution must turn over scientific data that it does not intend to introduce at trial but is nevertheless relevant because it was used by law enforcement as an investigative tool that yielded evidence and resulted in probable cause for an arrest.153 This type of lead-generating evidence includes photo management technology, facial recognition technology (“FRT”), and IGG.154 Regarding IGG, prosecutors are attempting to circumvent, with some degree of success, discovery rules that usually require DNA reports by law enforcement laboratories to be furnished to the defense, contending that the genealogical testing is being conducted by private companies and thus the reports and materials are not in their possession.155 Prosecutors also argue that the privacy interests of people unconnected to the crime and the “chilling effect” of disclosing proprietary information should outweigh the rights of defendants to receive copies of IGG-related materials.156 But these arguments are specious; the prosecution cannot insulate itself from its discovery obligations by outsourcing scientific testing to nongovernmental third parties. This would give prosecutors an unfair advantage by preventing access to information critical to cross-examining witnesses and testing the reliability and admissibility of the scientific evidence and may actually be exonerative. To the extent that there are proprietary and privacy issues, protective orders can address such concerns.
While there is limited case law on the scope of discovery permitted when IGG is used, rulings on the discoverability of photo management technology and FRT are illustrative of the issues with which courts are grappling.157 For example, photo management technology is used by police to generate pictures of potential suspects by putting into a computer database descriptive information, such as height, hair color, and race.158 This process is typically used when a suspect’s identity is unknown, but police have witness descriptions.159 In People v. Holley, New York’s highest court held that when the police use photo management technology to generate pictures of possible suspects, the prosecution must preserve and make available to the defense all photographs viewed by witnesses, as well as the order in which they were displayed.160 Significantly, even though the prosecution did not intend to introduce the unselected photographs into evidence at trial, Holley held that prosecutors were required to provide this information to the defense so it could assess whether the identification procedure was unduly suggestive.161
However, courts are divided as to the prosecution’s obligation to provide the defense with lead-generating information developed by other advanced technologies, such as IGG and FRT, a form of biometric data that pinpoints features on individuals’ faces to identify them.162 Like IGG, law enforcement nationwide uses FRT as an investigative step to identify or eliminate a suspect.163 Both IGG and FRT can be considered scientific techniques164 that produce scientific reports165 and cannot alone constitute probable cause for an arrest.166 In addition, neither requires its analysts to undergo training or receive any standardized education.167
Courts frequently consider privacy implications when determining whether information generated by FRT and IGG is subject to pretrial discovery.168 A review of the limited case law available in these areas shows that courts diverge on whether this type of scientifically and technologically produced information is discoverable.169 With respect to FRT, one New York trial court held that since it is merely an investigatory measure to identify and eliminate suspects and not “the basis for testimony at a trial,” a criminal defendant had no right to be given access to FRT material.170 Similarly, in another New York trial court, the defense argued the prosecution had not met its discovery requirements because it failed to turn over the entire FRT-generated candidate list of photographs.171 The court held that the requested information was not discoverable because the prosecution provided the photos viewed by the witness.172 Moreover, the court noted that the FRT lead was not the reason the defendant was arrested, and the prosecution stated it would not be using the information at trial.173 The court further ruled that the candidate list was not Brady material because providing the defense with all of the photos was comparable to requiring the prosecution to turn over every single image featured in a photo manager system or mug book that remotely looks like the defendant.174
Likewise, a Florida appellate court rejected a criminal defendant’s claim that he should have been given access to all the possible FRT matches as they would have enabled him to “cast doubt on the State’s case,” and the matches constituted Brady material since FRT contributed to his identification.175 The court held that the defendant was not entitled to the photos generated as possible matches for three reasons: (1) the defendant was unable to show that they “resembled him”; (2) his counsel asserted the FRT analyst would not be called as a witness because the analyst’s testimony would just validate the police officers’ testimony; and (3) the defendant was convicted following the jury’s comparison of the photo taken by the police of the person who sold them drugs with “confirmed photos of [the defendant]” and the defendant himself.176
By contrast, a New Jersey appellate court found FRT-related information was in fact discoverable in a criminal case where the technology was used to identify a defendant.177 The court held that the FRT material was necessary for the defendant to challenge his identification, question the reliability of the State’s investigation, establish a third-party liability defense, and raise issues regarding reasonable doubt.178 In its ruling, the court highlighted FRT’s “novel[ty],” the lack of testing related to it, and the potential for mistakes, concluding that the defendant should have the opportunity to prove that FRT is unreliable and led the police to implicate the wrong suspect. 179 In fact, studies have shown that if FRT generates more than one result, defendants have a convincing case for asserting a misidentification defense.180
3. Case Law Regarding the Applicability of Discovery Statutes to IGG Materials
Only four courts, three of which are in California, have considered whether the prosecution is obligated under applicable discovery statutes to provide the defense with information regarding its use of IGG.181 The California cases prohibited the defense from obtaining IGG materials. In People v. Waller, a California trial court addressed the defendant’s motion for access to IGG materials in a rape case.182 The issue before the court was the discoverability of the “familial searches of the private genetic genealogy databases,” the identity of the genetic genealogy company or companies, and the IGG “reports and communications.”183 The prosecution argued the defense was not entitled to this information because it was only intending to introduce at trial the STR comparison of the defendant’s DNA and the crime scene sample, rendering the IGG materials irrelevant.184 The State further argued this information was privileged under California’s discovery statute.185 The defense asserted that access to the IGG material was necessary because it was (1) potentially exculpatory, (2) essential for a possible suppression motion or Daubert reliability hearing, and (3) required to be disclosed in accordance with due process, Brady v. Maryland, and the defendant’s Sixth Amendment rights.186
The Waller court declined to give the defense access to the IGG materials,187 holding they were not discoverable.188 The California statute requires the prosecution to provide the defense with, inter alia, exculpatory evidence and statements or reports, such as medical examinations and scientific analysis, made by witnesses who will be called to testify.189 The court first found the IGG information to be irrelevant and immaterial.190 It reasoned that the materials did not create probable cause for the defendant’s arrest and were not used as evidence to prove the defendant’s involvement in the crimes, equating the IGG database to an informant who gave investigators a lead.191 The court summarily concluded without any detailed analysis that the IGG materials did not contain exculpatory information and would not bring about the discovery of exonerative information.192 The court further stated that access to the IGG information would not reasonably form the basis for third-party liability193 and that the defendant had no Fourth Amendment privacy claim regarding the genetic data since his DNA was not in the IGG database.194 In addition, the court rejected the defense claim that without the requested materials, it could not assess the IGG company’s reliability, stating that since the prosecution was not intending to introduce IGG evidence at trial, such information was irrelevant and immaterial.195 Moreover, the court mentioned that “the prosecution or others acting on their behalf” were not in possession of the evidence requested by the defense.196
The court further found that IGG information did not constitute Brady material because the defense failed to meet the requisite showing that it was “evidence favorable to the accused which [wa]s material to issues of guilt or punishment.”197 Furthermore, it held that the defense’s lack of access to the IGG materials did not implicate the defendant’s right to a fair trial.198 Finally, the court held that the IGG information was not discoverable because society’s interest in solving crimes weighed in favor of maintaining the confidentiality of the IGG company and its findings, as well as the police’s follow-up investigatory work to identify the defendant.199 The court explained that revealing this proprietary information to the defense would chill any future cooperation between law enforcement and IGG companies, reasoning that the materials were “not direct or circumstantial evidence” that would be presented by the prosecution nor necessary to mount a defense and therefore would not “deprive [the defendant] of a fair trial.”200
A similar ruling was made in In re Michael Green, where another California trial court considered whether a defendant charged with homicide was entitled to IGG information under the state’s discovery statute.201 The issue before the court was whether the IGG materials, including reports, matches and related data, the family tree, the laboratory technicians’ names and communications, and the laboratory’s accreditations, were required to be provided to the defense as part of discovery.202 The defendant argued he should have access to the information to present an adequate defense because (1) it could lead to the discovery of exculpatory information; (2) the SNP creation process may have been erroneously conducted; (3) it could provide evidence supporting claims of due process and Fourth Amendment violations; and (4) the defense had the right to interview other people deemed potential matches.203
The court held that the materials were not subject to discovery,204 ruling that the other potential matches had no significant impact on the case against the defendant.205 Rather, the court concluded the STR DNA test used to verify that the defendant was the perpetrator was more probative than the IGG evidence, finding that the preliminary IGG match was immaterial and not exculpatory.206 Like Waller, the Green court held that IGG was merely an investigatory lead and other measures were utilized to pinpoint the defendant, particularly the confirmatory STR test.207 The court found the STR test to be the only evidence required to be turned over, stating only the STR test was relevant to the defendant’s guilt or innocence.208 In denying the defense’s motion, the court highlighted the failure of the defendant to put forth evidence supporting the conclusion that any of the other potential matches might be the actual perpetrator.209 The court explained that the “mere possibility” that information could assist the defense was not enough to establish materiality and, therefore, was not required to be produced under the applicable discovery statute.210
Likewise, in People v. Simien, a third California trial court considered the discoverability of IGG materials in a sexual assault case.211 The defense sought access to all DNA information from the private genetic genealogy database(s) used to identify him212 because (1) it was “relevant real evidence” pursuant to California’s discovery statute; (2) it was necessary to help establish a third-party liability defense; (3) this request was similar to a request for information regarding a CODIS match; (4) it was required to be turned over under Brady v. Maryland; and (5) the Fifth and Fourteenth Amendments to the U.S. Constitution, as well as the California Constitution, made this information discoverable.213 The prosecution opposed turning this material over, asserting it was irrelevant and protected under California law.214 The court concluded that the prosecution was not required to turn over the IGG information.215 It reasoned that the defendant failed to establish the information’s relevance.216 The court said the defendant did not provide details with sufficient specificity to support his assertion that he may consider calling a witness to testify regarding IGG, including the particular expert he would use and how the IGG information would help his defense.217 The court further concluded that the defendant’s mere mention of a possible third-party culpability defense did not properly elucidate why the IGG material should be turned over.218 The court rejected the defendant’s argument analogizing the discovery request made in this case to the prosecution’s obligation to provide CODIS matches, finding it was unsupported by statutory and case law.219 Regarding the defendant’s Brady argument, the court ruled that the defendant failed to establish that the IGG information was “favorable and material” and stated that it was “[n]either exculpatory or useful to impeaching a prosecution witness.”220 The court found the IGG information used to identify the defendant as the suspect to be “simply irrelevant to guilt or punishment” because all it was used to do was “point[] the finger of suspicion.”221 In sum, these three California cases narrowly interpret the discovery rules to prevent the defense from obtaining access to IGG materials.
C. State v. Kohberger
By contrast, in State v. Kohberger, an Idaho court ruled that the state discovery statute applies to IGG materials. In Kohberger, four University of Idaho students were found stabbed to death in an off-campus home in November 2022.222 During its investigation, law enforcement located a Ka-Bar knife sheath partially underneath one of the victim’s bodies, which was seized pursuant to a search warrant.223 The Idaho State Police Lab located a single male DNA profile on the knife sheath, performed STR analysis, and entered the profile into CODIS but did not find a match.224 Investigators decided to use IGG, which was conducted by a private laboratory and the Federal Bureau of Investigations (FBI).225 Using social media, public records, and information available on the IGG database, the FBI constructed a family tree and pinpointed Bryan Kohberger as the suspect.226 Law enforcement verified Kohberger was the crime scene DNA depositor by collecting trash from his family’s home and conducting STR DNA analysis for comparison.227 The analysis showed the DNA belonged to the father of the individual who left the DNA at the crime scene.228 Law enforcement then obtained a DNA sample from Bryan Kohberger pursuant to a search warrant.229 STR DNA testing indicated the crime scene DNA and Kohberger’s DNA were a match.230 This evidence contributed to the probable cause used to arrest Kohberger and charge him with four counts of first-degree murder and one count of burglary.231
As part of pretrial discovery, Kohberger sought access to the IGG-related materials used by law enforcement.232 The State opposed the application and filed a motion for a protective order.233 The prosecutor argued the Idaho discovery statute did not require the information to be provided to the defense.234 In an argument based on Green, the prosecutor also contended the IGG information was not exculpatory and not required to be turned over to the defense since it was merely an investigatory tip that did not establish Kohberger’s guilt.235 The State further asserted the materials were irrelevant to the formation of a defense in this case because the evidence that will be used against the defendant is the confirmatory STR test, not the IGG results.236 The prosecution said it should not have to provide the defense with IGG information because the materials were not used in determining the probable cause for Kohberger’s arrest nor were they presented to the grand jury in connection with his indictment.237
The Idaho discovery statute requires the prosecution to turn over any evidence coming from or belonging to the defendant.238 The State contended the IGG reports and family tree were not received from Kohberger himself and he had no property interest in those materials.239 The prosecution also argued the IGG family tree was not discoverable because it cannot be considered “‘results or reports’ of ‘scientific tests or experiments.’”240 The prosecutor asserted that disclosure of the family tree information violates the privacy rights of individuals unconnected to the crimes.241 Due to the high-profile nature of the case, the State contended the personal information of innocent civilians identified through IGG must be shielded, classifying them as informants.242 The prosecutor also noted its concern that the IGG service would be harmed if the requested materials were disclosed because future customers would not use the company if they knew that their information could be turned over to law enforcement.243
The defense, however, asserted the IGG information was discoverable under Idaho’s discovery statute.244 The defense contended Kohberger had the right to know how the SNP profile was created and who else was deemed a candidate through IGG, adding that without this information, it would be unable to explore whether Kohberger’s DNA may have been planted at the crime scene.245 The defense further argued the IGG information utilized by law enforcement should be considered “results or reports from scientific investigations” under the Idaho discovery statute,246 and if the defense does not know which company conducted the IGG, it cannot properly investigate or question the methods used.247 In addition, the defense insinuated that the reason the State was reluctant to turn over these materials was because the FBI may have used databases without the permission of the IGG companies.248 Due to the limited case law available, the defense compared IGG to FRT, quoting the aforementioned ruling in a New Jersey FRT case to support its argument that access to the IGG materials are needed for an adequate defense.249
The trial court held a hearing on this issue,250 and both sides presented witnesses to support their arguments.251 Ultimately, the court decided to provide the defense with access to at least some of the IGG materials following in camera review.252 The court held that Kohberger met the minimum requirements to establish that the information in question was material to mounting his defense.253 During the hearing, experts, who were attorneys with extensive experience in DNA litigation, testified on behalf of Kohberger.254 They discussed the importance of defense access to the IGG information to (1) question the sufficiency of the police investigation; (2) conduct its own inquiry into whether Kohberger was the only suspect or there were viable alternatives; (3) challenge the reliability of the SNP and STR DNA profiles; and (4) object to the admissibility of other unspecified evidence.255 Based on the expert testimony, the court found that the IGG information was material and required to be disclosed because, inter alia, it falls within the ambit of Idaho’s discovery statute and would allow the defense to locate other evidence, effectively cross-examine witnesses, impeach or rebut the prosecutor’s arguments, and “alter the quantum of proof in [the defendant’s] favor.” 256
Moreover, the court declined to fully adopt the State’s argument that the family tree and IGG-related reports did not constitute scientific results or reports under Idaho’s discovery statute.257 It concluded that “the list of SNP profiles generated from the genealogy service(s) that connected with the suspect’s SNP profile” and the shared amount of DNA between those profiles are considered results of scientific tests that are discoverable.258 While the court did not find that the family tree constructed with “publicly available sources” and the FBI and private laboratory genealogists’ notes were scientific results or reports, it did conclude that these materials were considered police reports and thus discoverable.259 Ultimately, the court viewed the IGG materials in camera and provided the defense with access to at least some of them.260 The court went as far as to permit specific defense experts to view the discovery materials and allow “[t]he defense’s mitigation expert” who was crafting a family tree on behalf of the defendant to continue her work, as long as she did not use the materials that were turned over by the prosecution.261
II. Why IGG Materials Should Be Discoverable
Hailed as “one of the most significant scientific advancements of our era,” the extraordinary power and influence of DNA technology has left an indelible mark on the criminal justice system.262 Even John Roberts, the Chief Justice of the United States Supreme Court, singled out DNA evidence for its “unparalleled ability both to exonerate the wrongly convicted and to identify the guilty,”263 and study after study demonstrates the confidence Americans have in the accuracy of DNA analysis.264 The profound effect that the introduction of DNA evidence has on the process265 makes it all the more imperative that pretrial discovery rules are adapted to catch up to the growing sensitivity of DNA tests and their increasing use in serious felonies.
A. Statutory Review
Although the ABA recommends expansive pretrial discovery that includes all scientific “results or reports[,] . . . data, calculations, and documentation” regarding people and physical evidence, as well as “[a]ll law enforcement records created in the case,”266 in practice, state and federal law are far more restrictive when it comes to providing the defense access to these materials. Most discovery statutes are written so vaguely that they give prosecutors and courts broad latitude as to what should be turned over.267 Generally, when expert witnesses are being called by the prosecution, their reports are made available to the defense.268 However, discovery rules are not as clear in terms of potentially relevant examinations, test results, and other data and reports that are not going to be used at trial. A review of all state and federal discovery statutes shows that there are no uniform requirements for scientific and investigative reports. While all states to some degree consider scientific reports discoverable,269 thirty-one states and federal law require the defense to formally request such information.270 Only three states specifically mention DNA evidence.271 With respect to police reports, just seventeen states allow defense access to investigators’ reports, either automatically or by request.272 Thirteen states and federal law to some extent prevent the defense from having access to police notes and reports.273
B. Scientific or Police Reports?
The statutory definitions of scientific and police reports are generally so imprecise that they give prosecutors leeway to assert that IGG materials are not scientific in nature but are actually tantamount to police reports, since in most jurisdictions such a classification would exempt them from discovery.274 In states where police reports are discoverable,275 prosecutors have used another category for IGG to circumvent discovery, calling it “investigatory work.”276 The limited case law available elucidates the effect such classifications can have on access to IGG material that may be critical to mounting an effective defense. The Green court determined that IGG materials are not considered scientific and therefore not subject to discovery.277 On the other hand, the Waller court agreed with the prosecution that IGG materials are not discoverable because they are “protect[ed] information compiled by law enforcement.”278
The Kohberger court discussed the classification arguments, dividing the IGG materials into both scientific and police report categories in finding them potentially discoverable.279 The court classified as scientific results “the list of SNP profiles generated from the genealogy service(s) that connected with the suspect’s SNP profile and the percentage of DNA those profiles shared with the suspect profile.”280 It further deemed “the family tree and notes taken by FBI agents during their investigation” to be police reports and memoranda.281 The court held that the private laboratory’s reports and memoranda were discoverable, rejecting the argument that they were not in the prosecutor’s possession and not subject to the statutory provisions.282
Significantly, the court determined that the private laboratory was acting “as investigators in connection with the investigation of the case,” and therefore its reports and memoranda could be discoverable.283 In at least one case, the prosecution successfully argued that IGG materials were generated by a private, non-governmental entity to avoid turning over the information.284 Critically, some courts have held that private entities acting at law enforcement’s bidding should be deemed government agents, preventing prosecutors from hiding behind such inconsequential distinctions.285 While the issues in these DNA cases arose under different circumstances, these courts’ reasoning applies to IGG. For example, in a New York gun possession case in which DNA was found, the trial court held the defense was entitled, as part of discovery, to the raw electronic data underlying the laboratory’s DNA analysis program.286 The court ruled that the lab was “act[ing] as an agent of the prosecution, as much as the police department does.”287 The court noted the rapidly changing landscape regarding technology, stating that definitions of reports and documents should keep up with the times.288 Another New York court held that when a lab acts on behalf of police in analyzing crime scene DNA evidence, the reports are discoverable.289 New York and Minnesota appellate courts found that defendants would be deprived of due process if they were denied data and reports during discovery because the analyses were conducted by private, nongovernment laboratories.290
C. IGG Materials Should Be Discoverable Even if It Is Not Used by the Prosecution at Trial
The argument that IGG evidence should be excluded from discovery and limited only to evidence that will be presented at trial is equally dubious. In the few cases in which trial courts have ruled on discovery motions related to IGG, many of the prosecutors contended that since they were only planning to introduce the STR test that confirmed the defendants’ identities, the IGG materials are irrelevant.291 In fact, the Waller court’s decision to deny the defense access to IGG searches, “reports and communications,” and the identities of the IGG companies was in part based on the prosecution’s assertion that it was not going to introduce the information at trial and was neither relevant nor material to the defense’s case.292 In denying discovery,293 the Green and Waller courts ignored that IGG materials were clearly the underpinning of the DNA evidence that identified the suspects.
In United States v. Yee, an Ohio federal court ruled “that predicate materials relied on by experts who testify in support of admission of novel scientific evidence are encompassed within the provisions of [the discovery statute]” and should be turned over during pretrial discovery.294 The Yee defendants were seeking access to materials in connection with DNA testing conducted in a homicide case, including “matching criteria and standards . . . , tests conducted with reference to the effect of ‘environmental insults’ on the reliability of the DNA testing process, information about population data, . . . and results of proficiency testing.”295 Based on the holding in Yee, it stands to reason that the same predicate material standard should apply to IGG, a cutting-edge technology that generates background materials for DNA evidence the prosecution will present at trial. Indeed, if IGG materials are not discoverable, the defense may never learn the technique was used in the case,296 impeding its ability to assess and challenge evidence and expert testimony that will be introduced297 and providing the prosecution with a competitive advantage that will deprive a defendant of the right to a fair trial. The Kohberger court recognized this issue, stating that “at least some of the IGG information is material to the preparation of the defense” and necessary for the defense to question aspects of the prosecution’s case.298
D. The Novelty of IGG
Although DNA has become the gold standard of forensic evidence,299 technological advances, including the increased sensitivity of DNA testing, enable DNA to be utilized in novel ways.300 Some of the new uses of DNA, including IGG, have not been vetted by courts so there is little case law to review. IGG was first utilized in 2018 in the Golden State Killer case, which ended in a plea deal.301 Other cases that used the technology have also ended in pleas or gone through the trial process without dealing with reliability issues.302 Like IGG, probabilistic genotyping software is an innovative method of analyzing DNA samples too small or degraded for conventional techniques.303 This technology utilizes likelihood ratios to connect crime scene DNA profiles to suspects.304 Court decisions regarding the defense’s right to access source code information during discovery are instructive. Some courts have held that the information is not discoverable. For instance, New York’s highest court upheld a trial court’s denial of the defendant’s discovery request for access to the probabilistic genotyping source code because it was not considered “a ‘written report or document’” under the state’s statute, and the defendant did not indicate any other “particularized need for the source code.”305 Other courts found the source code to be subject to discovery. A New Jersey appellate court held that the source code should be turned over because the defendant needed access to it to question the prosecution’s expert during a Frye hearing about the software, and the judge required the information to effectively decide on the technology’s reliability.306 The court addressed the concern that trade secrets would be disclosed by issuing a protective order, finding that intellectual property interests are not “meant to justify concealing relevant information” in criminal pretrial proceedings.307
Moreover, courts are split regarding defendants’ rights to access information from lead-generating technology like IGG, such as FRT. Two New York trial courts declined to compel prosecutors to turn over all FRT matches,308 as well as information about the software itself.309 Conversely, a New Jersey appellate court ordered the prosecution to provide a wide range of FRT information to enable the defense to assess the software’s accuracy, question the credibility of the prosecution’s case, and establish reasonable doubt.310
With the increased use of IGG nationwide for cold cases and active investigations, it is imperative for the defense to gain access to all related materials to question the technology’s scientific reliability and acceptance through the Frye v. United States or Daubert v. Merrell Dow Pharmaceuticals standards before trial311 or challenge other evidence or expert testimony during the proceedings.312 At every step of the IGG process, there are numerous issues that can be raised by the defense during Frye or Daubert hearings to address unreliability. For example, without access to IGG materials, the defense cannot meaningfully articulate the lack of consistency in standards across laboratories, education, and qualifications for genealogists, and regulations for the SNP-testing technology and equipment.313 Furthermore, at trial, the defense requires IGG materials to challenge STR DNA evidence and related expert testimony. This information is needed to introduce issues regarding the crime scene sample used to create the SNP, including the high likelihood of degradation, small quantity, and multiple contributors.314 Making this argument is crucial to cast doubt on the defendant’s identification. The proprietary nature of the methodologies and source codes are of no moment.315 Due process and fundamental fairness should outweigh any concerns about the trade secrets of IGG laboratories.316
E. Exculpatory Material
Given the nature of IGG, which generates information about multiple candidates of interest,317 perhaps the biggest drawback in denying the defense access to the materials is that it may prevent defendants from acquiring potentially exculpatory material. Brady v. Maryland requires disclosure of exonerative evidence318 considered “‘material’ to the defendant’s case.”319 Most jurisdictions require prosecutors to disclose “exculpatory information that can lead to admissible evidence, even if the exculpatory information is not admissible in its current form.”320 Significantly, Brady applies to information that “lead[s] to probable cause, not only material that establishes probable cause.”321 If IGG materials generate leads that end up creating probable cause for an arrest, it must be provided to defendants so they can mount effective defenses and adequately question the reliability and sufficiency of the prosecution’s case.322 In Kohberger, the prosecutor argued the IGG information was “not favorable to [the d]efendant on the issues of guilt or punishment” and was in fact inculpatory, not exculpatory.323 In addition, the prosecution characterized IGG as “nothing more than a tip” that focused investigators on the suspect.324 While that may ultimately be the case, it is unfair to leave the decision as to whether the materials are potentially exculpatory in the sole discretion of the prosecutor.
At the very least, the defense should be provided with enough information to challenge the investigation’s reliability due to law enforcement’s “fail[ure] even to consider [an alternate suspect’s] possible guilt,” as the Supreme Court held in Kyles v. Whitley.325 In Kyles, the Court concluded the prosecution’s failure to disclose an alternative suspect constituted a Brady violation.326 Notably, the Court found the defense needed this material to effectively challenge the quality of the police work.327 Likewise, the genealogists’ methodology and the alternate matches can potentially be used to cast doubt on the prosecution’s case and the reliability of law enforcement’s investigation.328 As to the issue raised by the Kohberger prosecutors that the privacy of unconnected individuals may be violated by revealing family trees and other possible matches,329 such concerns are secondary to due process and the interest of justice, especially given the trial’s gravity as a death penalty case.330 Ensuring the defendant receives a fair trial, with every opportunity to scrutinize evidence and challenge its admissibility and reliability, should be the paramount concern in this—and every other—criminal case.
III. Proposal
To guarantee due process, discovery statutes should be amended or interpreted to specifically require all IGG materials be turned over to the defense during pretrial discovery. If IGG is used to identify a defendant, prosecutors must disclose this information to the defense. Thus far, it appears that prosecutors and law enforcement have voluntarily acknowledged IGG’s use.331 However, such disclosures should be mandated by statute to ensure the ability to mount an adequate defense, including scrutiny of the process to ascertain whether it was done in a reliable and scientifically acceptable manner, expose exculpatory material, and prepare for cross-examination.332 To that end, all IGG information should be discoverable, and the following materials should be furnished to the defense:
(1) the name of the laboratory and all reports and records related to the conversion of the crime scene DNA into a SNP profile, such as the accreditations and certifications and the specific methodology for the process;333
(2) a list of the laboratory analysts and genealogists who created the SNP profile and family trees;334
(3) all information regarding the crime scene DNA used to make the SNP profile, including the source (e.g., blood or semen), the amount, quality, and age of the sample, and the number of contributors;335
(4) documentation as to who provided the sample to the laboratory and how and where it was stored;336
(5) the name of the IGG database(s) used to find family members of the crime scene DNA depositor and whether law enforcement disclosed to users that it was searching the database as part of a criminal investigation;337
(6) documentation related to whether police obtained a warrant to search the IGG database(s) and the basis upon which it claimed there was probable cause for such an investigation;338
(7) any notes, reports, and memoranda for the IGG process, including family trees, bench notes, and communications between genealogists and law enforcement;339
(8) the materials used to construct family trees, such as birth and census records and other media sources, including newspapers;340
(9) the individuals’ identities in the family trees and their relation to the candidate(s) of interest;341 and
(10) the names of potential suspects provided to law enforcement by genealogists and law enforcement documentation as to who was or was not investigated, including the basis for excluding other candidates.342
The optimal way to ensure that IGG materials be turned over during pretrial discovery is to amend discovery statutes to specifically require the defense be given access to this information. Due to the difficulties in getting amendments through the legislative process, including the time and political considerations involved, short of statutory changes, courts should liberally interpret the existing statutes to make IGG information discoverable.343 Whether IGG ends up being classified as scientific or police reports largely will depend on how the statute is written. Courts always have the option of requiring access to IGG information based on its materiality to mounting an effective defense. While the language varies from state to state, there is always some statutory provision to cover this type of evidence.344
Although legitimate concerns related to privacy and proprietary rights have been raised,345 courts have the authority to issue narrowly tailored protective orders in limited circumstances to shield trade secrets and unconnected individuals’ identities.346 Ultimately, the interest of justice, where an individual’s liberty is at stake, must be the main consideration, and law enforcement and prosecutors should be barred from keeping the process cloaked in secrecy. As IGG becomes widespread,347 subjecting such novel technology to rigorous examination will improve the technique and ensure responsible, scientifically reliable usage. Transparency will inure to the benefit of the defense and the criminal justice system as a whole.
Conclusion
The increasing use of IGG to identify suspects in criminal cases has exposed a flaw in the pretrial discovery process enabling prosecutors to prevent scrutiny of this cutting-edge technology and access to potentially exculpatory information. Prosecutors are exploiting ambiguities in discovery statutes, which vary between jurisdictions, to avoid turning over IGG-related material to the defense during pretrial discovery.348 As a novel derivative of traditional DNA profiling,349 considered the gold standard in forensic evidence,350 it is even more imperative that IGG be subjected to rigorous examination. Furnishing data related to this new technique protects a defendant’s right to a fair trial and enables the accused to mount an effective defense. Although amending discovery statutes to include IGG would be optimal, the interpretation of existing statutes may be a more expeditious resolution. Transparency will improve IGG for use by the prosecution and defense attorneys alike, guarantee due process, and advance the constitutionally guaranteed right to a fair trial.