Here's why the Idaho student murder suspect may have chosen to 'stand silent' in court, experts say

Bryan Kohberger, the man accused of stabbing four Idaho college students to death, sat wordlessly in court during his arraignment on Monday as a judge read aloud the murder and burglary charges against him and asked whether the suspect was prepared to announce his plea.

Instead of entering a plea, Kohberger's attorney replied, "Your honor, we are standing silent."

The unconventional legal strategy, also known as "standing mute," relies on an Idaho criminal rule which requires a judge to then enter a not guilty plea on the defendant's behalf, effectively allowing him to avoid verbally committing to being guilty or not guilty.

"It doesn't matter what he says or doesn't say," Seattle attorney Anne Bremner told CNN. "Either way, he's on the record with a not guilty plea."

Though highly unusual, standing silent is not unheard of. The tactic was also used in the case against Nikolas Cruz, the gunman responsible for the 2018 massacre at Marjory Stoneman Douglas High School in Parkland, Florida.

As the October trial looms, Kohberger faces four counts of first-degree murder and one count of burglary for the November 13 killings of University of Idaho students Kaylee Goncalves, 21; Madison Mogen, 21; Xana Kernodle, 20; and Ethan Chapin, 20, in an off-campus home in Moscow, Idaho.

Though a sweeping gag order has largely shrouded details of the case from the public, investigators have said Kohberger, a graduate student in the Department of Criminology at nearby Washington State University, broke into the victims' home and stabbed them repeatedly before fleeing the scene.

The gruesome killings and prolonged investigation blanketed the college campus and surrounding city in uncertainty and apprehension. After nearly seven weeks, Kohberger was arrested and identified as the alleged killer.

There are a number of reasons defendants may choose to "stand silent," especially in such a high-profile and highly scrutinized case as Kohberger's, according to University of Idaho law professor Samuel Newton.

The defendant may want to avoid criticism that could come with a certain plea, Newton said. A not guilty plea, for example, may spark public outrage that they are not taking responsibility for their alleged actions, he explained.

Prosecutors and defense attorneys may also be negotiating behind the scenes, potentially discussing a plea agreement, Newton said.

Bremner dismissed the idea that the move could indicate Kohberger's attorney may be considering a plea of not guilty by reason of insanity because there is no insanity defense in Idaho.

Or, Newton added, it could simply be that the defendant is being difficult and not wanting to cooperate.

Bremner echoed that possibility, saying, "Maybe he's just trying to be defiant or attempting to show he's the smartest guy in the courtroom." She pointed to Kohberger's background as a criminology student, noting, "He knew enough about criminal studies that it would have an impact."

What happens next for Kohberger

Kohberger has been held without bail since he was arrested in December at his parents' home in Pennsylvania and brought back to Idaho, where he awaits trial.

The trial is set to begin October 2 and is expected to last about six weeks.

Prosecutors have 60 days from Monday to announce, in writing, whether they plan to seek the death penalty in their case against him.

Two hearings are also scheduled for June 9 to address motions, filed by an attorney representing the family of Goncalves and a media coalition, regarding concerns over the wide-ranging gag order in the case.

The restriction currently prohibits prosecutors, defense lawyers, attorneys for victims' families and witnesses from publicly discussing details of the case that are not already public record.

Investigators detail evidence against the suspect

After Kohberger was arrested, investigators laid out some of the evidence that led them to home in on the 28-year-old as their suspect, including surveillance footage, a witness account and DNA evidence.

A key lead came from surveillance footage which caught a white Hyundai Elantra near the victims' home that night, according to a probable cause affidavit. The vehicle, which was later found by police at Washington State University in nearby Pullman, Washington, was registered to Kohberger, authorities said.

Kohberger's driver's license information was consistent with a description of the suspect given to police by once of the victims' surviving roommates, officials said.

The roommate told investigators that she saw a masked figure clad in black in the house on the morning of the killings, according to an affidavit. She described the person as "5'10" or taller, male, not very muscular, but athletically built with bushy eyebrows," it said.

As the investigation was still ongoing, Kohberger drove cross-country to his parents' house in Pennsylvania, arriving there about a week before Christmas, Monroe County Chief Public Defender Jason LaBar told CNN in December.

There, investigators were finally able to connect Kohberger to the crime scene by linking DNA found in trash collected from his family's home to DNA on a tan leather knife sheath found lying next to one of the victims, the affidavit said.

A cache of items was seized from the Pennsylvania home after the suspect's arrest, including a cell phone, black gloves, black masks, laptops, a Smith and Wesson pocket knife and a knife in a leather sheath, according to an evidence log.

Authorities also seized a white 2015 Hyundai Elantra an attorney for the suspect previously said he'd used to drive, accompanied by his father, to his parents' home for the holidays.

The vehicle was dismantled by investigators, who collected parts, fibers and swabs for further examination, court documents show.