Chris Watts was sentenced to life in prison without the possibility of parole

On Thursday, Colorado authorities released surveillance footage showing Chris Watts loading up his pickup truck hours after he killed his pregnant wife and two young daughters.

The video — captured by a neighbor’s security camera in the early morning hours of Aug. 13 — is among the trove of documents and videos prosecutors have released since Watts was sentenced to life in prison Nov. 19 for murdering pregnant wife Shanann, 34, and their daughters Bella, 4, and Celeste, 3.

In the footage, which was obtained by PEOPLE but was edited below by CBS Denver, Watts can be seen loading a gas can into the bed of his truck. Next, the video shows Watts backing the vehicle into his home’s garage.

Investigators believe Watts used that very truck to transport the bodies of his family to a remote oil work site, where they were found days later. The girls, who’d been smothered by Watts’ bare hands, were found stuffed in oil tanks, while Shanann, who’d been strangled, was buried in shallow grave.

Shanann Watts and her daughters, Celeste and Bella

Prosecutors posit Watts — after backing the truck into the garage — likely placed the three bodies in the bed before driving them to the oil work site.

Before his arrest, Watts spoke to local media, pleading for the safe return of his wife and kids.

But authorities learned he was having an affair with co-worker Nichol Kessinger and killed his family in the hopes of having a new start with his mistress.

Chris Watts and Nichol Kessinger
| Credit: Weld County District Attorney's Office

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Before Watts was sentenced, he pleaded guilty. As part of his plea agreement, he avoided the death penalty.

Shanann spent much of the summer before the killings in North Carolina with her parents and the couple’s children while Watts stayed home in Colorado and conducted his affair with Kessinger.

During this time, Shanann tried to save their marriage by giving Chris books on self-help and relationship counseling. But Chris had already mentally checked out of the marriage and ignored them, even throwing one of the books in the garbage.