Authorities investigating the murders of four University of Idaho students are likely using forensic genetic genealogy — by comparing DNA evidence to genealogical family databases, an expert said in a new interview.
The Idaho State Police Forensic Services is testing 113 pieces of physical evidence collected at the bloody scene, Fox News reported.
Experts typically start off by comparing unknown DNA samples to the FBI’s Combined DNA Index System — or CODIS, a database containing genetic samples of known offenders — by using STR (short tandem repeat) DNA analysis.
“It’s pretty quick to compare against CODIS. Had they gotten a match, I think they probably would have arrested by now, so I think we can assume that they are at least looking at using investigative genetic genealogy,” CeCe Moore, chief genetic genealogist at Parabon NanoLabs in Reston, Va., told Fox News Digital.
“It just depends how quickly they learned they didn’t have a match in CODIS as to when that would have been done,” added Moore, one of the most successful genetic genealogists working with law enforcement in the US.
If that preliminary analysis comes up short, investigators may analyze more than a half-million DNA single nucleotide polymorphisms, or SNPs, in the search for possible distant relatives of a suspect, Fox News reported.
Experts can reverse-engineer a person’s family tree using traditional genealogy and narrow it down to a possible suspect, from whom they can surreptitiously try to extract a DNA sample, according to the news outlet.
Moore and her team recently used genetic genealogy to analyze DNA in the 1975 cold-case murder of Lindy Sue Biechler, 19, in Pennsylvania.
Male DNA was recovered from the victim’s underwear but investigators did not get a hit in CODIS.
The Parabon Labs scientists secretly obtained fresh DNA from a coffee cup that a suspect threw in the trash earlier this year.
The sample came back as a match for DNA taken from the crime scene — leading to the arrest of David Sinopoli, 68, who now faces homicide charges, Fox News reported.
“They always need that extra step of collecting DNA, and it’s usually going to be surreptitious because they don’t want to tip someone off,” Moore told the outlet.
Investigators can often obtain DNA samples from a killer who used a knife to commit a crime.
“Typically, in cases I’ve worked with stabbings, if someone stabs enough times, the knife almost always slips,” Moore told Fox News Digital.
“You almost always get the perpetrator’s DNA mixed in with the victim’s DNA,” she added.
Meanwhile, Matthew Gamette, the director of the Idaho State Police Forensic Services, warned that investigations are time-consuming.
“I certainly can’t share case-specific information,” Gamette told the Idaho Statesman. “I can tell you that our scientists are working very hard.
“These things don’t necessarily come out in the media. Investigators are getting information that hopefully is helpful to their investigation, and we’ll continue to work at the state lab as we do 365 days of the year,” he added.
State Police spokesperson Aaron Snell told the paper that investigators are still receiving analyses and test results from the state lab.
Officials have previously said the results will not be disclosed to the public, according to the Statesman.
Gamette said it’s vital that investigators receive a “DNA profile” from cells in the body to help identify a suspect through genetic makeup.
In Idaho, the CODIS database includes DNA from convicted felons and evidence from other crime scenes, he told the paper.
Investigators also can turn to the national database, whose entries from some states include not only felons but also people arrested on suspicion of a felony, Gamette added.
As for the use of molecular forensic genetic genealogy, Gamette said the state crime lab doesn’t have the cutting-edge technology, but noted that it could contract for the work.
He declined to comment to the Statesman on any specifics related to the murder investigation.
On Wednesday, police revealed they were searching for the occupants of a white Hyundai Elantra who may have “critical information” about the quadruple homicide, which claimed the lives of Kaylee Goncalves, 21, Madison Mogen, 21, Xana Kernodle, 20, and Kernodle’s boyfriend Ethan Chapin, 20.
Read More: Idaho student murders’ investigators likely comparing DNA evidence to FBI database
