Attorneys for Bryan Kohberger, the man accused of killing four University of Idaho students last year, are requesting a judge dismiss the indictment against him.
In a Tuesday court filing, the lawyers argued that the grand jury was "misled as to the standard of proof required for an indictment." They said the Idaho state Constitution sets the standard of proof for a grand jury at beyond a reasonable doubt.
The filing said the grand jury was "erroneously instructed" with the standard of proof required for a presentment, which requires a preliminary hearing.
"The failure to properly instruct a Grand Jury as to the standard of proof is grounds for dismissal of the Indictment," the filing states.
If the judge refuses to dismiss the indictment, defense attorneys could ask for a preliminary hearing to determine whether the case should move forward.
Former federal prosecutor Neama Rahmani told Fox News Digital the latest motion "is another frivolous defense motion. The standard of proof at the grand jury or preliminary hearing stage is probable cause, not beyond a reasonable doubt."
"Kohberger’s lawyers are filing every possible motion to create an appellate issue," she said. "They know they have a greater chance of getting a death sentence reversed on appeal than convincing a death penalty qualified jury not to return a guilty verdict and death sentence "
Kohberger was a graduate student at Washington State University studying criminology when he fatally stabbed Ethan Chapin, 20; Madison Mogen, 21; Xana Kernodle, 20; and Kaylee Goncalves, 21, on Nov. 13 in an off-campus house, authorities said.
He is now accused of burglary and four counts of first-degree murder. Authorities have not revealed a motive. A judge entered not guilty pleas on Kohberger's behalf in May.
According to court documents, Kohberger allegedly stalked the King Road rental home a dozen times before the murders and returned once more hours after the slayings but before police arrived.
A six-week trial is scheduled to begin on Oct. 2.