At Wednesday’s hearing in the murder trial of Bryan Kohberger, who is accused of killing four University of Idaho students in November 2022, genetic genealogy evidence in the case will be discussed. 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 investigative genetic genealogy, or IGG, evidence.
“This request is based on Mr. Kohberger’s 6th Amendment right to the effective assistance of counsel and counsel’s continuing 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 did not object to the material being shown to the three defense experts but objected to what were vaguely called “criminal investigators.” Prosecutors said they should at least have been named and said the defense had failed to make a “sufficient” argument for why they should see the information.
Although small in scope, Wednesday’s hearing on the issue reflects the defense’s interest in closely examining investigative genetic genealogy evidence and its use in the investigation.
The powerful forensic method has become widely disseminated among law enforcement investigators over the past few years. This method has been used to solve some of the country’s most vexing cold cases, most notably the 2018 arrest of the Golden State Killer.
But genetic genealogy has rarely been tested extensively in the courtroom. Questions remain about how investigators obtained and used forensic technique in this case, as well as about broader constitutional evidence and privacy concerns.
“This is still a very new investigative technique,” said Jennifer Lynch, general counsel of the Electronic Frontier Foundation, a nonprofit that advocates for civil liberties on the Internet. “I think the public needs to know more about how these types of searches are done so we can make sure police aren’t willy-nilly collecting DNA from people and running it through consumer genetic genealogy databases.”
Let’s take a look at how investigative genetic genealogy works in general, its relevance to the Idaho student murders case, and why Kohberger’s defense is focusing on it.
How does investigative genetic genealogy work?
Genetic genealogy is a practice that blends 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 easier for millions of people to take at-home DNA tests and learn more about their origins, family, and health characteristics. Neither site allows the public or law enforcement to access their databases of genetic information.
Still, consumers can upload their DNA files to other public websites, such as GEDmatch, to learn about connections to others who have uploaded their DNA files to the site. From there, users can seek to learn about their family legacy, such as informing adopted children about their biological parents, by scanning public information such as obituaries, birth certificates, or social media profiles.
The practice began with hobbyists looking to learn family histories, but in recent years has expanded into the world of forensics to try to solve cold cases and other violent crimes.
In the field of forensics, investigators occasionally come across a crime scene where DNA evidence, such as blood or semen, is found but no specific suspect is present. Investigators can take this unknown person’s DNA and compare it to DNA profiles in the FBI’s CODIS database to see if it’s a match to a known criminal. However, if there is no match, the identity of the perpetrator may be unknown.
Investigative genetic genealogy combines these two fields. This way, criminal investigators can take the DNA profile of an unknown suspect and upload it to a public database to obtain information about the suspect’s family members. Investigators can then use genealogical information and other evidence to reconstruct the family tree and identify potential suspects.
Investigators then do general detective work to narrow down the suspect pool to a single person. This may mean looking at people’s age, location, physical appearance or ability to commit the crime.
How to use the method in this case
In the case of the Idaho student murders, the use of investigative genetic genealogy remains somewhat unclear.
On Sunday, November 13, 2022, police in Moscow, Idaho were called to a home near the University of Idaho and found the fatally stabbed bodies of four students inside: Kaylee Goncalves, Madison Mogen, Ethan Chapin, and Xana Kernodle.
In the following days, authorities said they had no murder weapon or suspect. But investigators found a tan leather knife sheath at the scene, and the Idaho State Laboratory found a single source of male DNA on the sheath’s button snap, according to a probable cause affidavit.
Investigators targeted Kohberger, then a doctoral student in criminology at nearby Washington State University, using surveillance video of a vehicle in the area around the time of the murders and physical descriptions of the suspect, according to testimony. a surviving witness and his cell phone location data. Detectives also obtained DNA from a trash can at the Kohberger family’s Pennsylvania home and compared it to DNA on the casing, finding that “a male cannot be excluded as the biological father of the Suspect Profile,” according to the affidavit. Kohberger was later arrested on December 30, 2022.
In all, the genetic genealogy relevant to the investigation was not specified in the arrest warrant or any search warrant in the case.
But court documents filed by prosecutors in June 2023 revealed that the FBI originally uploaded the DNA profile from the knife’s sheath to public genealogy sites. According to prosecutors, “the FBI began constructing family trees of genetic relatives of suspect DNA left at the scene in an effort to identify the person contributing the unknown DNA” and then sent a tip to investigate Kohberger.
According to the application, the tip “led law enforcement to the Defendant, but did not provide law enforcement with any concrete evidence of his guilt.”
That filing also stated that prosecutors used traditional “STR” DNA comparison, a common type of DNA profile used in criminal cases, and found a “statistical match” with DNA taken from Kohberger’s knife.
Why is the defense bringing this issue up?
The prosecution argued that the investigative genetic genealogy was not specified or used in the warrants and would not be presented at trial, so it was irrelevant to the case. But Kohberger’s defense argued that they should have had the right to access all DNA data used in the case, including material from the FBI’s genetic research process, to better prepare for their defense.
Last October, Latah County District Court Judge John Judge ruled that Kohberger’s team had the right to see some materials in preparation for his defense.
“The State’s argument that the IGG investigation was not used in obtaining any warrants and was completely irrelevant because it would not be used at trial is well supported,” the judge wrote. “However, Kohberger has the right to view at least some of the IGG information in preparing his defense, even if it is ultimately found to be irrelevant.”
The judge said he will review investigative genetic genealogy information to determine what should be shared and issue any necessary protective orders. In January, following that review, he ordered some IGG material to be shared with the defense team, but he sealed the material.
Lynch, general counsel of the Electronic Frontier Foundation, has written about broader legal issues related to genetic genealogy. He said the technique threatened to violate people’s 4th Amendment rights, which prohibit unreasonable searches, saying their DNA is private.
“There’s a tendency among judges and the public to say: ‘Oh, these crimes are so horrific that they justify any search to identify the person,'” he said. “But we need to understand that such investigative techniques are not limited to unsolved cases and serious crimes. “They will be used even in the smallest crimes and can push people to commit crimes they did not commit.”
CNN’s Taylor Romine contributed to this report.
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