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. They will make their arguments during a two-day hearing starting Thursday morning, part of which will be 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.

“There would be no investigation into him without that original constitutional violation,” attorneys Jay Weston Logsdon and Ann Taylor wrote in a court filing. They later continued, “Without IGG, there is no case, no request for his phone records, surveillance of his parents’ home, no DNA taken from the garbage out front. Because the IGG analysis is the origin of this matter, everything in the affidavit should be excised.”

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.

Latah County Prosecutor Bill Thompson and the rest of the prosecution team say there is nothing unconstitutional about the use of IGG, noting that Kohberger’s relatives voluntarily provided their own DNA to a genetic genealogy service. They’ve also argued in court filings that case law is clear: Defendants have no reasonable right to privacy for DNA that is left at the scene of a crime.

The defense team also says that once Kohberger was identified as a possible suspect, law enforcement officers either purposely or recklessly lied or omitted crucial information when they asked the court to issue search warrants for his apartment, his parents’ house, his car, his cellphone and even for his own DNA. They want all of that evidence kept out of the trial as well.

Specific details about the alleged police misconduct are hidden from public view, however; 4th District Judge Steven Hippler has kept most of those court filings, along with many of the court documents on the IGG evidence, under seal. Part of the hearing starting Thursday will be held behind closed doors because the judge says he doesn’t want potential jurors “tainted” by hearing about any evidence that might not be allowed in trial.

On Wednesday, a coalition of news organizations including The Associated Press asked the judge to reconsider the secrecy.

“In any criminal case, I would submit that it’s of extreme public interest to know whether a law enforcement officer sworn to tell the truth … made reckless or false statements” during an investigation, the news organizations’ attorney, Wendy Olson, said during a hearing on Wednesday. The U.S. Supreme Court has found that the public and the press have a First Amendment right to open court proceedings, she said, and that open courts also help to protect the rights of the accused.

“Openness and transparency are more important than ever in maintaining and restoring confidence in our government institutions,” Olson said.

The judge was unswayed.

“I don’t think much has changed in terms of the need to protect the jury pool here, given the intense media scrutiny that has and continues to follow this case,” Hippler said. “We will be challenged under the best of circumstances in obtaining a jury that has not been overly exposed to this … and in particular, exposed to evidence that may not come into this trial.”

The judge said no one would be allowed into the courtroom but that the open portions of the hearing would be livestreamed from the court’s YouTube page.