A hearing Wednesday in the murder case against Bryan Kohberger, the man accused of killing four University of Idaho students in November 2022, will discuss the genetic genealogy evidence in the case — an issue his attorneys say is a key part of his research. defense.
In a filing in early February, the defense asked the court to allow three defense experts and unnamed “criminal investigators” to view the sealed genetic genealogy (IGG) evidence.
“This request is based on Mr. Kohberger’s 6th Amendment right to effective assistance of counsel and counsel’s continued duty to investigate the case against Mr. Kohberger,” attorney Anne C. Taylor wrote. “Access to these materials is necessary to investigate how and when Mr. Kohberger was identified as a suspect.”
In response, prosecutors had no objection to showing the material to the three defense experts, but did argue with the vaguely named “criminal investigators.” Prosecutors said they should at least be named and said the defense failed to provide an “adequate” argument for why they needed to see the information.
Although minor, Wednesday’s hearing to discuss the matter reflects the defense’s interest in closely examining the genetic genealogical evidence and its use in the investigation.
The powerful forensic method has spread widely among law enforcement investigators in recent years. It has been used to solve some of the country’s most frustrating cold cases, most notably the 2018 arrest of the Golden State Killer.
But genetic genealogy has rarely been tested intensively in a courtroom. And questions remain about how investigators obtained and used the forensic technique in this case, as well as broader constitutional evidentiary and privacy issues.
“This is still a very new investigative technique,” said Jennifer Lynch, general counsel of the Electronic Frontier Foundation, a nonprofit that defends civil liberties online. “I think the public should have the opportunity to learn more about how these types of searches are conducted so that we can ensure that police are not simply collecting people’s DNA and comparing it to consumer genetic genealogy databases. ”
Here’s a look at how investigative genealogy works in general, its relevance to the Idaho student murders case and why Kohberger’s defense has focused on it.
How investigative genetic genealogy works
Genetic genealogy is a practice that combines DNA analysis in the laboratory with genealogical research, such as tracing a person’s family tree.
Genetic testing companies like 23AndMe and Ancestry have made it easy for millions of people to take at-home DNA tests and learn more about their ancestry, families, and health traits. Neither site gives members of the public or law enforcement agencies access to their genetic knowledge database.
Still, consumers can upload their DNA file to other public websites, such as GEDmatch, to learn about connections with other people who have also uploaded their DNA files to the site. From there, users can search public information, such as obituaries, birth certificates or social media profiles, to try to learn more about their family heritage, such as informing adopted children about their biological parents.
The practice started with hobbyists interested in learning about their family history, but in recent years has expanded into the world of forensics to solve cold cases and other violent crimes.
In the field of forensics, investigators occasionally come across a crime scene with DNA evidence, such as blood or semen, but no specific suspects. Detectives can take the DNA of this unknown person and compare it to DNA profiles in the FBI database CODIS to see if there is a match with a known criminal perpetrator. But if there is no match, the identity of the perpetrator may remain unknown.
Investigative genetic genealogy combines these two fields. It allows detectives to take the DNA profile of an unknown suspect and upload it to a public database to learn more about the suspect’s relatives. Researchers can then use the genealogical information and other evidence to search the family tree and identify potential suspects.
From there, investigators do general detective work to narrow the suspect pool to one person. This may include looking at people’s age, location, physical appearance or ability to commit the crime.
How the method was used in this case
In the case of the Idaho student murders, the use of genetic genealogy for research remains a bit unclear.
On Sunday, November 13, 2022, police in Moscow, Idaho, were called to a home near the University of Idaho and inside they found the fatally stabbed bodies of four students: Kaylee Goncalves, Madison Mogen, Ethan Chapin, and Xana Kernodle.
In the days that followed, officials said they had no murder weapon or suspect. However, investigators found a brown leather knife shell at the scene, and the Idaho State Lab found a single source of male DNA on the button closure of the shell, according to a probable cause statement.
According to the affidavit, investigators zeroed in on Kohberger, then a doctoral candidate in criminology at nearby Washington State University, by using surveillance video from a vehicle in the area around the time of the killings, physical descriptions of the suspect from a surviving witness and his cell phone location data. Furthermore, detectives recovered DNA from the trash at the Kohberger family’s home in Pennsylvania and compared it to the DNA on the casing, identifying “a male as not ruled out as the biological father of Suspect Profile,” according to the affidavit. Kohberger was subsequently arrested on December 30, 2022.
Overall, genetic genealogy for research was not mentioned in the arrest warrant or in any search warrant in the case.
However, court documents filed by prosecutors in June 2023 revealed that the FBI originally uploaded the DNA profile from the knife sheath onto public genealogy sites. “The FBI went to work building family trees of the genetic relatives of the suspect DNA left at the crime scene in an attempt to identify the contributor of the unknown DNA,” and then sent a tip to investigate Kohberger, prosecutors said.
The tip “pointed law enforcement authorities to (the) defendant, but did not provide law enforcement authorities with substantial evidence of guilt,” the filing said.
That filing also stated that prosecutors used a traditional “STR” DNA comparison, a common form of DNA profiling used in criminal cases, and found that Kohberger was a “statistical match” to the knife’s DNA.
Why the defense keeps bringing it up
The prosecutor has argued that genetic genealogy for research was not mentioned or used in the arrest warrants and will not be presented at trial, so it is therefore not relevant to the case. However, Kohberger’s defense has argued that they should have the right to access all DNA data used in the case, including material from the FBI’s genetic genealogy research process, to better prepare for their defense.
Last October, Latah County District Court Judge John Judge ruled that Kohberger’s team has the right to see some of the material in preparation for his defense.
“The State’s argument that the IGG investigation is entirely irrelevant as it was not used in obtaining arrest warrants and will not be used at trial is well supported,” Judge wrote. “Nevertheless, Kohberger has the right to see at least some of the IGG information in preparing his defense, even if it ultimately proves irrelevant.”
The judge said he would review the genetic genealogy research information to determine what should be shared and issue any necessary protective orders. In January, after that review, he ordered some of the IGG material to be shared with the defense team, although he placed that material under seal.
Lynch, the general counsel of the Electronic Frontier Foundation, has written about the broader legal issues with genetic genealogy. She said the technique threatens to violate people’s Fourth Amendment rights, which ban unreasonable searches, and says people’s DNA is private.
“There’s a tendency among judges, among the public, to say, ‘Oh yeah, these crimes are so terrible that it warrants any kind of investigation to possibly identify the person,’” she said. “But what we need to realize is that these types of investigative techniques are not limited to cold cases and are not limited to heinous crimes. They will be used even in minor crimes, and they can accuse people of crimes they did not commit.”
CNN’s Taylor Romine contributed to this report.
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