Bryan Kohberger drove for hours after the Idaho student murders before surveillance cameras caught him calmly shopping and using a self-checkout register.

Police in Moscow, Idaho, have released hours of surveillance videos they would have used as evidence at trial if the 30-year-old former criminology Ph.D. student hadn’t pleaded guilty at the last minute to avoid the potential death penalty.

The clips offer a glimpse at how police were able to trace his movements even though he had his phone shut off at the time of the murders, and how the socially awkward murderer tried to get into a Costco store but was apparently turned away without showing a membership card.

At a news briefing after Kohberger’s sentencing in July — the first police held since his arrest on Dec. 30, 2022 — detectives said they believed they would have found him without the knife sheath by focusing on the suspect vehicle.

WATCH: Kohberger’s Elantra spotted near crime scene before the Idaho murders

The videos include numerous clips taken by surveillance cameras throughout the route to and from the crime scene, showing what appears to be Kohberger’s white Hyundai Elantra in various locations before and after the murders.

WATCH: Surveillance video shows Kohberger’s Elantra near Idaho crime scene

Kohberger had several minor encounters with police in Moscow and nearby Pullman, Washington, before the slayings, even though he’d only been studying at Washington State University for a few months. The stops, which were recorded on police bodycam video, helped detectives link him to the vehicle.

He also changed his license plate after the murders, switching from a Pennsylvania registration to a local one.

Madison Mogen, top left, smiles on the shoulders of her best friend, Kaylee Goncalves, as they pose with Ethan Chapin, Xana Kernodle, and two other housemates in Goncalves’ final Instagram post, shared the day before the four students were stabbed to death. (@kayleegoncalves/Instagram)

Kohberger is serving four consecutive life sentences with no chance of parole, plus another 10 years. As part of the plea deal, he waived his rights to appeal or seek a future sentence reduction.

This still image taken from surveillance video of an Albertson’s supermarket in Clarkston, Washington, shows Bryan Kohberger shopping hours after the Idaho student murders. (Moscow Police Department)

Fox News’ Olivia Palombo and Kyle Schmidbauer contributed to this report.