(NewsNation) — Attorneys for Idaho college killings suspect Bryan Kohberger asked a judge to dismiss most of the evidence in the case, which they believe relies on a genetic investigation process they say is unconstitutional.
Kohberger’s defense team also argues the search warrants in the case were tainted by police misconduct. They made their arguments during a two-day hearing starting Thursday.
If successful, their motion could significantly disrupt the prosecution’s case ahead of the trial, which is set to begin in August.
Prosecutors say the investigation, including the use of genetic genealogy, was properly done.
Part of Thursday’s hearing was held behind closed doors, which the judge said is meant to avoid potential jurors being “tainted” by hearing evidence that might not be allowed in trial.
During the public portion of the hearing, the judge appeared skeptical of the defense arguments regarding the constitutionality of the search.
Prosecutors: Bryan Kohberger’s DNA on knife sheath
Kohberger’s attorneys argue law enforcement violated his constitutional rights when they used investigative genetic genealogy, or IGG, to identify possible suspects.
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 reportedly identified Kohberger as a possible suspect.
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 parent’s 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. Judge Steven Hippler has kept most of those court filings, along with many of the court documents on the IGG evidence, under seal.
Bryan Kohberger can face death penalty if convicted
Kohberger, accused of killing four University of Idaho students on Nov. 13, 2022, can face the death penalty if convicted, a judge ruled last November.
Kohberger’s defense team sought to remove the death penalty as a possible punishment, but Hippler denied its request.
The deaths of Madison Mogen, 21; Kaylee Goncalves, 21; Xana Kernodle, 20; and Ethan Chapin, 20, shocked the small town of Moscow. Initially, investigators had few leads and spent considerable time tracing the activities of the four students in the hours prior to their deaths.
NewsNation digital producer Liz Jassin and The Associated Press contributed to this report.