Police seized masks and weapons from family home of Idaho murder suspect Bryan Kohberger

A .40-caliber Glock 22 pistol and "black face masks" were found, according to search warrant documents.

Bryan Kohberger, who is accused of killing four University of Idaho students, leaves an extradition hearing at the Monroe County Courthouse in Stroudsburg, Pa., on Jan. 3.Matt Rourke / AP

Police seized face masks, a .40-caliber Glock 22 pistol — popular with law enforcement — and a knife from the family home of Idaho murder suspect Bryan Kohberger, court documents revealed Thursday.

When police arrested Kohberger in Pennsylvania, investigators took "black face masks," the weapon, three empty magazines for the Glock and a Smith & Wesson pocketknife, according to newly unsealed search warrant documents.

A witness who said she stood in "frozen shock phase" when four University of Idaho students were slain Nov. 13 described the suspect as "a figure clad in black clothing and a mask that covered the person's mouth and nose walking towards her," according to the court documents.

The suspect’s attorney in Idaho could not immediately be reached for comment Thursday morning.

Kohberger is accused of killing the four students early Nov. 13. All four victims — Ethan Chapin, 20, Kaylee Goncalves, 21, Xana Kernodle, 20 and Madison Mogen, 21 — were fatally stabbed.

Even though a firearm was not used, John Jay College of Criminal Justice professor Michael Alcazar said there is still potential evidentiary value in the seized gun.

The attacker could have had it with him the night of the murder and have victims' DNA on it, and police are surely going to test it for connections to any unsolved crimes, Alcazar said.

"Maybe he has the gun on his person when he committed these crimes. He might have blood, saliva, sweat from the victims and transferred it to the weapon," said Alcazar, a retired New York City police detective who teaches introduction to criminal investigations.

The family home of murder suspect Bryan Kohberger in Albrightsville, Pa.TODAY

“There might be some unsolved shootings or homicides we can link to this weapon,” he said. “I would absolutely test that weapon for that.”

The Glock 22 is touted by its manufacturer as one of its most popular police service weapons.

At the time of the slayings, Kohberger was a doctoral student studying criminal justice and criminology at Washington State University in Pullman, a short drive over the state line from Moscow. A WSU official has said Kohberger is no longer enrolled.

The suspect's and the victims' two universities are just 10 miles apart, and residents of the two college towns — Pullman, Washington, and Moscow, Idaho — regularly travel the short distance to each.