A former Federal Bureau of Investigation detective says that hair follicles of the suspect in a quadruple homicide on Nov. 13 near the University of Idaho may lead authorities closer to making an arrest as forensic testing of evidence is beginning to be shared with authorities.

Ethan Chapin, 20; Xana Kernodle, 20; Madison Mogen, 21; and Kaylee Goncalves, 21, all University of Idaho students, were killed during the early morning hours of Nov. 13 between 3 and 4 a.m. and police have not yet identified a suspect. Police say the victims were stabbed multiple times, with some showing signs of defensive wounds based on an autopsy conducted by the Latah County Coroner. 

Authorities recovered over 113 pieces of "physical evidence" from the crime scene, which was sent to the Idaho State Police Forensic Services crime lab. Idaho State Police Communications Director Aaron Snell told WHD News Digital on Wednesday that investigators have begun to receive results from forensic testing of some evidence.

Former FBI special agent Jonathan Gilliam told WHD News Digital that if the suspect left hair follicles at the crime scene, it could help lead investigators to a potential suspect.

UNIVERSITY OF IDAHO MURDERS TIMELINE: WHAT WE KNOW

A split photo showing the school and the victims, including University of Idaho students Ethan Chapin, 20; Xana Kernodle, 20; Madison Mogen, 21; and Kaylee Goncalves, 21.  (Derek Shook for WHD News Digital/Jazzmin Kernodle via WHD/ Instagram/ @kayleegoncalves)

"If [the attacker is] standing over them and he's stabbing ferociously, then he could have hair follicles that could fall off, his own skin could shed on there, if he cut himself and it bled on her. If they do their collection diligently, then they will find those particles of DNA, and then they'll have that," Gilliam commented as authorities begin to receive results from forensic testing.

Gilliam noted that DNA testing is a "very detailed exercise" that takes time to process, adding that authorities are likely working through a process of elimination.

Front view of the house where four Idaho students were killed. (Adam Sabes/WHD News Digital)

"So many people were in there, the fact that they're young people means the DNA may not come back to anything," Gilliam said. "But with a house like that and you're talking about 10 to 40 people a week and even more, there's a tremendous amount of of DNA that is repeated. Already right there, you're looking at 50 different people, strands of DNA."

"They're going to get those, separate those, and then try to see if they can place those with somebody," he added.

IDAHO MURDERS: HANDPRINT SPOTTED NEXT TO EVIDENCE TAPE AT HOUSE WHERE FOUR STUDENTS WERE KILLED

A side-view of the house in in Moscow, Idaho, on Tuesday, November 22, 2022 where four students were slain. (Derek Shook for WHD News Digital)

Police say that between 10 p.m. and 1:30 a.m., Goncalves and Mogen were at the Corner Club bar located in Moscow before being spotted nearby at Grub Wandering Kitchen's food truck at 1:40 a.m. The two arrived at the King Road home at 1:56 a.m. after being driven by a "private party" that police don't consider a suspect.

Chapin and Kernodle were at the University of Idaho Sigma Chi fraternity house before returning to the King Road home at 1:45 a.m. on Nov. 13, police say. 

IDAHO POLICE SAY THOUSANDS OF TIPS RECEIVED AS COLLEGE MURDER PROBE NEARS THREE WEEKS WITH NO SUSPECT

A memorial for the slain students at the University of Idaho, Monday, November 28, 2022 is covered in snow. The menorial is in honor of the victims of a quadruple homicide involving in an off-campus home on November 13. (Derek Shook for WHD News Digital)

The 911 call was made at 11:58 a.m. on one of the two surviving roommates' cell phone. Police say that the two roommates didn't wake up until later in the morning on Nov. 13.

While police haven't yet identified a suspect in the attack, authorities remain confident that the attack was targeted.

"Our clarification last night directly addressed comments made by Latah County Prosecutor Thompson, who said the suspect(s) specifically looked at this residence, and that one or more of the occupants were undoubtedly targeted. We remain consistent in our belief that this was indeed a targeted attack but have not concluded if the target was the residence or its occupants," a statement from the Moscow Police Department to WHD News on Thursday read.

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Anyone with information about the incident is being asked to call Moscow police at 208-883-7054 or email tipline@ci.moscow.id.us.

WHD News' Stephanie Pagones, Cristina Coleman, and Alexandria Hernandez contributed to this report.