by A hearing Wednesday in the murder trial of Bryan Kohberger, the man accused of killing four University of Idaho students in November 2022, is set to discuss the genetic genealogy investigation evidence in the case – an issue his attorneys said is the most an integral part of it. protected.
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, or IGG, investigative evidence.
“This request is based on Mr. Kohberger’s 6th Amendment right to the effective assistance of counsel and the ongoing duty of counsel to investigate the case brought 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 did not object to showing the material to the three defense experts, but instead confronted the vaguely called “criminal investigators.” Prosecutors said they should at least be named and said the defense had failed to make a “sufficient” argument as to why they needed to see the information.
Although limited in scope, Wednesday’s hearing to discuss the issue reflects the defense’s interest in closely examining genetic genealogy investigative evidence and its use in the investigation.
The powerful forensic method has become widespread among law enforcement investigators in recent years. It has been used to crack some of the country’s most frustrating cold cases, most notably the arrest of the Golden State Killer in 2018.
But genetic testing is rarely done rigorously in a courtroom setting. And questions remain about how investigators obtained and used the forensic technique in this case, as well as broader concerns about constitutional evidence and privacy.
“This is still a very new investigative technique,” said Jennifer Lynch, general counsel of the Electronic Frontier Foundation, a nonprofit organization that protects online civil liberties. “I think the public should have the ability to know more about how this type of search is done so we can make sure the police aren’t just collecting DNA from people and running it against consumer genetic databases. “
Here’s a look at how investigative genetic genealogy works in general, its relevance to the case of the Idaho student murders and why Kohberger’s defense focused on it.
How investigative genetic genealogy works
Genetic genealogy is the practice of combining DNA analysis in the laboratory with genealogical research, such as tracing a person’s family tree.
Genetic testing companies like 23AndMe and Ancestry make it easy for millions of people to take DNA tests at home and learn more about their heritage, families and health characteristics. Neither site allows the public or law enforcement to access their database of genetic information.
Still, consumers can upload their DNA file to other public websites, such as GEDmatch, to learn about connections with others who have also uploaded their DNA files to the site. From there, users can comb through public information, such as obituaries, birth certificates or social media profiles, to try to learn about their family heritage, such as informing adopted children about their biological parents.
The practice began with hobbyists interested in learning about their family history but in recent years the forensic world has expanded to try to solve cold cases and other violent crimes.
In the field of forensics, investigators occasionally arrive at a crime scene with DNA evidence, such as blood or sperm, but there is no specific suspect. Investigators can take the DNA of this unknown person and compare it to DNA profiles in the FBI’s CODIS database to see if there is a match to a known criminal offender. But if there is no match, the identity of the actor may remain unknown.
Investigative genetic genealogy marries these two fields. With it, criminal investigators can build a DNA profile of an unknown suspect and upload it to a public database to learn about the suspect’s family members. Investigators can then use the genealogical information and other evidence to build back through the family tree and identify suspects.
From there, investigators do general detective work to narrow the suspect pool down to one person. This can mean looking at the age, location, physical appearance or ability of people to commit the crime.
How the method was used in this case
In the case of the Idaho student killings, the use of investigative genetic genealogy remains somewhat unclear.
On Sunday, November 13, 2022, police in Moscow, Idaho, were called to a house near the University of Idaho and inside found the bodies of four fatally shot students: Kaylee Goncalves, Madison Mogen, Ethan Chapin and Xana Kernodle.
In the days that followed, officials said they did not have a murder weapon or a suspect. However, investigators found a tan leather knife sheath at the scene, and the Idaho State Lab found one source of male DNA on the button of the sheath, according to a probable cause affidavit.
According to the affidavit, investigators led Kohberger, then a Ph.D. student in criminology at nearby Washington State University, to the home using surveillance video of a vehicle in the area around the time of the killings, a description physical on the suspect from a surviving witness and his cell phone location data. In addition, detectives took DNA from the trash at the Kohberger family home in Pennsylvania and compared it to the DNA on the sheath, and identified “a male as not excluded as the biological father of the Suspect Profile,” according to the affidavit. Kohberger was then arrested on December 30, 2022.
Overall, no investigative genetic genealogy was mentioned in the arrest warrant or any search warrants in the case.
However, court documents filed by prosecutors in June 2023 revealed that the FBI uploaded the DNA profile from the sheath knife onto public genealogy sites. “The FBI went to work building a family tree of the genetic relatives to the suspect DNA left at the crime scene in an effort to identify the unknown DNA contributor,” and then sent a tip to investigate Kohberger, according to prosecutors.
The tip “directed law enforcement toward (the) Defendant, but did not provide substantial evidence of guilt to law enforcement,” according to the filing.
That filing also said prosecutors used a traditional “STR” DNA comparison, a common type of DNA profiling used in criminal cases, and found that Kohberger was a “statistical match” to the DNA from the knife.
Why does the defense keep giving it up
The prosecution argued that investigative genetic genealogy was not mentioned or used in the warrants and will not be presented at trial, so it is not relevant to the case. However, Kohberger’s defense argued that they should be entitled to access all the DNA data used in the case, including material from the FBI’s genetic genealogy investigation process, to better prepare their defense.
Last October, Latah County District Court Judge John Judge ruled that Kohberger’s team had the right to see some of the material in preparation for his defense.
“The State’s argument that the IGG’s investigation is completely irrelevant since it was not used to obtain any warrants and will not be used at trial is well supported,” the Judge wrote. “However, Kohberger is entitled to see at least some of the IGG information while preparing his defense even if it is ultimately determined to be irrelevant.”
The Judge said he would review the genetic genealogy investigation information to determine what needs to be shared and issue any necessary protective orders. In January, following that review, he ordered that some of the IGG’s content be shared with the defense team, although he kept that content under seal.
Lynch, general counsel of the Electronic Frontier Foundation, wrote about the broader legal issues surrounding genetic genealogy. She said the technique threatens people’s 4th Amendment rights that violate unreasonable searches, saying people’s DNA is private.
“Judges, to the public, tend to say, ‘Oh, well, these crimes are so horrific that it justifies any kind of search to identify the person,'” she said. “But we must understand that these investigative techniques are not limited to cold cases and not limited to heinous crimes. They will even be used in petty crimes, and they can frame people for crimes they did not commit.”
CNN’s Taylor Romine contributed to this report.
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