Inside the Deceptions of Chris Watts Before He Murdered His Wife and Children

In the weeks before Chris Watts murdered his pregnant wife and two daughters, he was spinning a web of deception that included an affair with a co-worker who thought he was already separated.

Watts' deceptions are profiled in the new Netflix documentary about his infamous case.

The documentary, entitled American Murder: The Family Next Door, began streaming on Netflix on September 30. It includes rarely seen text messages and letters between Watts and his wife.

On August 13, 2018, Watts strangled his wife, Shanann, in their home. Then he drove her body to a job site at the oil company where he worked. He disposed of his wife's body and then smothered his daughters — Bella, 4, and Celeste, 3. After pleading guilty to the murders, he received a life sentence.

Chris Watts, at left, with Shanann Watts

Before the murders, Shanann took the girls from their Colorado home to spend several weeks with her family in North Carolina. Chris Watts joined them after five weeks -- but was suspiciously unaffectionate.

"He kissed me once since he's been here," Shanann texted a friend. "That was at airport. I kissed him no grabbing my ass, hug or anything. I want to cry. 5 weeks away from me and not touching me.”

Later, she texted that she felt sexually rejected by Chris.

"I'm over here crying in silence,” she texted the friend. "He's never been like this. 5.5 ducking [sic] weeks no sex. Unless he was getting it somewhere else."

As it turns out, Watts was already embroiled in an affair with Nichol Kessinger, a colleague from work. Upon learning about Shanann's murder, Kessinger cooperated fully with police, giving several interviews about the man who she had thought was single. The documentary highlights some of these interviews.

"He lied about everything," Kessinger told police at one point, adding that she had thought Watts was a "great guy" before learning the truth. She said had started talking to him after noticing that he wasn't wearing a wedding ring.

RELATED: Chris and Shanann Watts' Final Texts Before He Killed Her Are Revealed in New Netflix Doc

CBI

Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

Chris Watts, at left, with Shanann Watts

RELATED: Chris Watts Is 'Triggered' by Netflix Documentary, Which 'Makes Him Feel a Lot of Shame': Source

After his arrest for murder, Watts continued to lie -- first in a series of televised interviews, and then to police. He finally consented to a polygraph examination.

During the polygraph, cops asked Watts several probing questions about Shanann's whereabouts and if he was lying about when he had last seen her. Watts failed the polygraph test badly, getting one of the possible lowest scores on it. A score of -4 is considered failing a polygraph. Watts scored a -18.

American Murder: The Family Next Door is available on Netflix.