BOISE, Idaho (AP) Prosecutors say Bryan Kohberger’s defense team will argue at his murder trial that someone else could have planted a knife sheath with Kohberger’s DNA at the home where four University of Idaho students were killed in 2022.

Latah County Prosecutor Bill Thompson made the claim in a motion filed in the case this week.

“Instead of challenging the conclusion that the DNA on the knife sheath belonged to Defendant, the defense’s expert disclosures reveal that the defense plans to argue the DNA on the knife sheath does not prove Defendant was ever at the crime scene and the knife sheath itself could have been planted by the real perpetrator,” Thompson wrote.

Many of the court documents detailing both sides’ plans for expert witnesses have been sealed, so it’s not currently possible to compare Thompson’s characterization of the defense plans against the defense team’s own court filings.

Kohberger is charged with four counts of murder in the deaths of Ethan Chapin, Xana Kernodle, Madison Mogen and Kaylee Goncalves, students who were killed in the early morning of Nov. 13, 2022, at a rental home near their 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.

Prosecutors have said they matched “touch DNA” found on a knife sheath near one of the victims to DNA taken from Kohberger using investigative genetic genealogy, or IGG techniques. Defense attorney Anne Taylor pushed to have the investigative genetic genealogy thrown out of the case, but 4th District Judge Steven Hippler denied that request last month.

Still, prosecutors say they don’t intend to refer to the IGG evidence during the trial and will instead tell jurors that a “tip” led them to Kohberger as a suspect.

Kohberger’s trial is scheduled to begin August 11 and expected to last more than three months.