BOISE, Idaho (AP) — Attorneys for a man charged with murder in connection with the killings of four University of Idaho students are asking a judge to throw out most of the evidence in the case because they say it all hinges on an unconstitutional genetic investigation process.

Bryan Kohberger’s defense team also contends that the search warrants in the case were tainted by police misconduct. A two-day hearing on the matter started Thursday, and much of it was closed to the public. If they are successful, it could throw a major wrench in the prosecution’s case before trial starts in August.

Kohberger is charged with four counts of murder in the deaths of Ethan Chapin, Xana Kernodle, Madison Mogen and Kaylee Goncalves, who were killed in the early morning of Nov. 13, 2022, at a rental home near campus in Moscow, Idaho. When asked to enter a plea last year, Kohberger stood silent, prompting a judge to enter a not-guilty plea on his behalf. Prosecutors have said they will seek the death penalty if Kohberger is convicted.

Kohberger’s attorneys say law enforcement violated his constitutional rights when they used a process called Investigative Genetic Genealogy, or IGG, to identify possible suspects.

“The court should suppress the IGG identification and everything that flows from that,” defense attorney Anne Taylor told the judge Thursday, shortly after the hearing was opened to the public. “There was no warrant for several phases of the search that led to the IGG work, and we think for every single one of those stages a warrant was required.”

The IGG process often starts when DNA found at the scene of a crime doesn’t yield any results through standard law enforcement databases. When that happens, investigators may look at all the variations, or single nucleotide polymorphisms, that are in the DNA sample. Those SNPs, or “snips,” are then uploaded to a genealogy database like GEDmatch or FamilyTreeDNA to look for possible relatives of the person whose DNA was found at the scene.

In Kohberger’s case, investigators said they found “touch DNA,” or trace DNA, on the sheath of a knife that was found in the home where the students were fatally stabbed. The FBI used the IGG process on that DNA and the information identified Kohberger as a possible suspect.

Taylor said police never sought warrants to analyze the DNA found at the crime scene, nor did they get warrants to analyze the DNA of potential relatives that had been submitted to genealogy databases. Then, she said, the FBI violated its own Investigative Genetic Genealogy interim policy by running the data through a database that wasn’t approved under the policy.

Deputy Attorney General Jeff Nye, one of the prosecutors, said there is nothing unconstitutional about the use of IGG. Kohberger isn’t asserting that he provided his own DNA to a genealogy site and then had it misused, Nye said, and defendants don’t have any right to privacy for DNA left at a crime scene.

The U.S. Department of Justice policy for IGG doesn’t exclude other legal investigative techniques, Nye said. Even if FBI investigators used an online genealogy database that wasn’t included in the policy, at most that might be a violation of the terms of service of the online database — not a violation of Kohberger’s rights.

Kohberger has been “wishy-washy” on the whole subject of DNA, said Nye.

“He’s trying to say, ‘It’s not my DNA and the state can’t prove that,’ but he’s also trying to say he has standing” to argue that the DNA was used in violation of his own privacy rights, said Nye. “That’s not how the Fourth Amendment works.”

Taylor also said that once Kohberger was identified as a possible suspect, law enforcement officers purposely lied and omitted crucial information when they asked the court to issue search warrants for his apartment, his parents’ house, his car, his cellphone and for his own DNA. She said all of the resulting evidence should be kept out of the trial.

One of the witnesses interviewed by law enforcement said she was intoxicated and unsure about her memories about when she heard other people moving around the house the night and morning of the murders, Taylor said. The witness later told investigators that she wasn’t sure if the memories were a dream or real, Taylor said.

But those details were purposely left out of court affidavits written by police when they were seeking search warrants, she said, to make the case seem stronger than it was. The magistrate who signed the search warrants might not have done so if all the information had been presented, Taylor said.

Other details, including which way Kohberger’s car was facing when it was picked up by cameras or when his cellphone pinged nearby towers was also not accurately conveyed to the magistrate in warrant applications, she said. Instead, the affidavits were written to make it look like Kohberger was stalking the house or following people — and that never happened, she said.

“The real story is exculpatory to Mr. Kohberger. He was not stationary around that house. He was never at that house,” said Taylor. “He did go to Moscow, he did drive around, but he was never there. And the phone records absolutely show that.”

Deputy Prosecuting Attorney Ashley Jennings said law enforcement used the most up-to-date information that they had available when they asked the court for search warrants. Jennings said that’s how the process is supposed to work.

“The defense has failed to back up this claim” that law enforcement officers made deliberate, reckless and false claims, Jennings said. “That’s because they can’t.”

The hearing is expected to continue on Friday, and will be livestreamed from the court’s YouTube page.