SEE IT: How investigators began to suspect Chris Watts murdered his pregnant wife and two young daughters [VIDEO]

A popular YouTube personality has analyzed police bodycam footage of the initial response to a 911 call reporting that Shannan Watts and her two daughters were missing.

Shannan’s friend Nicole Atkinson called police with concerns over the pregnant mom when she couldn’t reach her on August 13. The Weld County District Attorney’s office subsequently released police bodycam footage of those first critical hours of the investigation, when police searched the Watts home in Frederick, Colorado; also speaking to potential witnesses and reviewing security camera footage provided by a neighbor.

Derek Van Schaik, described as a business expert and body language reader on his website, posted a 37-minute compilation of bodycam footage on his YouTube channel, and provided commentary at certain intervals where he identified what he believed to be indications that police may have begun to question if Chris Watts had a role in his family’s disappearance.

At one point in the footage, a young man believed to be Nicole Atkinson’s son is heard, faintly, saying that he believes Chris Watts is lying, and that he “can’t keep his stories straight.” At that time, police had already contacted Watts by phone and were waiting for him to come home. Schaik notes that police may have had an early suspicion about an interior lock on the front door, which had been pulled closed, preventing Shannan’s friend from entering the home even though she had a key. Schaik speculates that it may have appeared that Chris Watts went out of his way to make sure no one could get into the home while he was at work.

The video also shows the moment officers, still at Chris’s home with Atkinson, reveal the news that Chris’s neighbor has told police that he has surveillance footage of the Watts home, and that is showed only Chris leaving the home.

And when Chris Watts and police go to the neighbor’s home to look at the footage together, Watts appears increasingly nervous, pacing and fidgeting and appearing to sweat.

Later that week, Chris Watts confessed to killing his wife in a rage after claiming to witness her strangling their daughter. Less than two months later, Watts pleaded guilty to killing all three of his family members and is currently serving multiple life sentences without the possibility of parole.