(NewsNation) — The attorney for Bryan Kohberger claims searches of his home and car yielded no traces of DNA from any of the four University of Idaho students he is accused of killing last fall.

Kohberger’s defense team made the claim in a Thursday court filing seeking to compel prosecutors to reveal how they analyzed DNA profiles collected at the crime scene.

“There is no explanation for the total lack of DNA evidence from the victims in Mr. Kohberger’s apartment, office, home or vehicle,” public defender Anne Taylor said in the filing.

Kohberger is charged with first-degree murder in the deaths of Ethan Chapin, Xana Kernodle, Madison Mogen and Kaylee Goncalves. The four students were found stabbed to death Nov. 13 inside their off-campus rental home.

Police allege cellphone tower data shows Kohberger was in the vicinity of the home multiple times in the days and weeks leading up to the stabbings.

Prosecutors have also said in court filings DNA on a knife sheath left at the scene matches Kohberger’s. His defense attorneys are seeking more information about a process called genetic genealogy testing that police initially used to help identify the DNA contributor.

Genetic genealogy works by taking a DNA sample and looking for matches in a public database. After a family tree is built, law enforcement can then identify a likely suspect from whom to collect a DNA sample for comparison to DNA found at a crime scene.

Prosecutors asked in a June 16 filing to keep secret the names of “hundreds of innocent relatives” on the family tree, as well as the name of the genetic genealogy services used.

“The State apparently only wants to prevent Mr. Kohberger from seeing how the (investigative genetic genealogy) profile was created and how many other people the FBI chose to ignore during their investigation,” Taylor write in her filing opposing the request.

“In essence, the State argues that if the later STR testing is accurate then there is no reason to concern ourselves with how the State came to investigate Mr. Kohberger,” she added.

A hearing on the matter is scheduled for 1:30 p.m. local time Tuesday.

The DNA on the knife sheath is, at this point, the only evidence prosecutors have revealed that directly links Kohberger to the crime scene.

That none of the victim’s DNA was found on Kohberger’s property doesn’t come as a surprise to Dave Aronberg, a Florida state prosecutor.

“He had a lot of time to clean it up,” Aronberg said Monday on “CUOMO.” “Remember, the murder didn’t occur at his home, it occurred at their home, so I’m not surprised there isn’t blood or DNA evidence found in his home. I don’t think it matters too much.”

Defense attorney and legal analyst Mark Geragos disagreed.

“This is as big a bombshell as people are making it out be,” Geragos said.