Idaho student killings: suspect’s DNA allegedly matches knife sheath at scene

The suspect accused of murdering four University of Idaho students in their beds was linked to the slayings after authorities tested his family's household trash for DNA and found a match on a knife sheath at the scene, according to court documents released on Thursday.

The newly disclosed filing also portrays a chilling account of survival, with one roommate telling police that the mask-clad killer walked past her as he left.

Bryan Christopher Kohberger, 28, a criminology graduate student, landed on law enforcement radar after security camera footage near the house revealed a white sedan drove by their home four times shortly before the early-morning murders.

After the discovery , authorities released a "be-on-the-lookout" alert apprising law enforcement to watch for the vehicle.

A security officer at Washington State University - where Kohberger attended - happened upon a Hyundai Elantra matching the description. The officer ran the license plate, which has a Pennsylvania tag, and learned the vehicle was registered to Kohberger.

The owner's driver's license description matched the description provided by one of the surviving roommates, who according to court documents opened her bedroom door shortly after 4am on 13 November after she heard crying.

She saw a tall, white male "clad in black clothing and a mask that covered the person's mouth and nose walking towards her". She said he was about 5ft 10in or taller, with an athletic build and "bushy eyebrows".