On the surface, Chris and Shanann Watts seemed to have the perfect marriage. Photo / Supplied
Speculation is mounting on the identity of the co-worker accused triple killer Chris Watts was sleeping with before he allegedly murdered his wife and their young daughters last week.
In the past week, the names of up to four women have been posted on closed internet forums dedicated to the case that has gripped America, as amateur sleuths race to work out her identity.
In court papers released on Monday, investigators said they learned Mr Watts was "actively involved in an affair with a co-worker," something he denied in earlier conversations with police, reports news.com.au.
Three of the four names put forward as Mr Watts' possible mistresses are long-haired brunettes like his wife while the fourth is a blonde, married family friend with young children of her own.
Some of the women worked alongside Christopher and Shanann as brand promoters for the Le-Vel company, which makes weight loss patches, while one is employed with Anadarko Petroleum, where Watts was an operator.
Shanann's body was found buried in a shallow grave in an Anadarko oilfield north of Denver on August 16 while Bella, 4, and Celeste, 3, were found submerged in nearby oil tanks, according to police arrest affidavit.
The 33-year-old has told authorities he killed his wife, 34, in a fit of rage after witnessing her "actively strangling" Celeste on the baby monitor as Bella lay spreadeagled, "blue" and apparently dead nearby.
As speculation intensifies over the identity of his so-called mistress, a forensic profiler has detailed chilling personality similarities between Mr Watts and Scott Peterson, who murdered his pregnant wife Laci in California in 2002 to be with his lover.
Like Peterson, who was convicted of first-degree murder in Laci's death, and second-degree murder of their unborn son in 2004, Mr Watts gave multiple interviews pleading with the public to help find his missing family.
"If somebody has her and they're not safe, I want them back now. That's what is in my head. If they're safe right now, they're going to come back," Mr Watts said in a TV interview outside the family home in Frederick, Colorado.
"But if they're not safe right now, that's the not-knowing part. Last night I had every light in the house on, I was hoping that I would just get ran over by the kids just running in and barrel-rushing me, but it didn't happen. And it was just a traumatic night trying to be here."
There were no tears as he calmly recounted the last time he'd seen his young family and at times he appeared to suppress a smirk — a sign, experts say, of the joy a subject feels when they believe they're successfully duping someone.
Forensic profiler Dale Yeager says Mr Watts presents as a less charismatic version of Scott Peterson.
"There are very clear personality connections between Chris (Watts) and Scott Peterson, except for the fact that Chris seemed to be less outgoing and is not as dynamic as Scott," he told Hollywood Life.
Dr Yeager says that there are "key factors" in Mr Watts' case that could "lead him" to allegedly murder his family and hide the bodies.
"There was an incredible amount of debt; the couple was irresponsible in the way they were spending money," he said. "All the fundamentals are there for this kind of behaviour — the financial stress and stress in the marriage."
Watts denied cheating on his wife when initially questioned by police but admitted to it after investigators uncovered the affair and confronted him, according to the police affidavit.
"For Chris to (allegedly) make the leap from adultery to murder (means) he had to be at a point where he could get to such a dark place, mentally, that he could justify very ugly, evil behaviour," Dr Yeager said.
"People who cheat don't have a moral compass. If you commit adultery in a relationship, you are a vile person because you're a liar and a con-artist. You don't care about the people you hurt, including your own children."
The profiler said it was likely Mr Watts was a narcissist.
"People make excuses for this bad behaviour and they're so narcissistic that they don't care who it hurts," he said. "Narcissism is like selfishness on steroids and it includes a certain amount of delusion … He can justify it all day, but what he's saying is he feels justified in lying and deceiving the people closest to him."
In a bombshell affidavit released on Monday, Mr Watts shifted the blame for the trio's deaths on his wife, who was fifteen weeks pregnant with a son they planned to call Niko.
In the documents, he claims the pair had an "intense conversation" after she returned from a work trip in the early hours of August 13. He said they had both cried after he told her he wanted to separate.
According to the affidavit, Mr Watts told authorities he went downstairs and a few minutes later witnessed her "actively strangling" Celeste via a baby monitor.
He said the screen also showed their other daughter, Bella, "sprawled out on her bed and blue".
"Chris said he went into a rage and ultimately strangled Shanann to death," the document said.
Police found surveillance video from a neighbour showing Mr Watts' truck backing into the driveway at 5.27am and then driving away from the house.
Mr Watts said he loaded his wife and daughters' bodies into the back seat of his truck and drove to an Anadarko Petroleum work site about 65km east of the family's home.
He buried Shanann's body and "dumped the girls inside" oil tanks, according to court documents.
Separate documents filed by Mr Watts' legal team last week said the girls' bodies were submerged in crude oil for four days before police found them late last Thursday.
Their mother's body was found in a shallow grave nearby, prosecutors said.
Mr Watts gave police an aerial photograph and identified three areas where he placed the bodies. Investigators searched with a drone and spotted a bedsheet that matched other linen in the family home and fresh dirt.
Shanann's social media accounts are filled with photos and videos of the girls playing with their father and the couple smiling. They married in North Carolina nearly six years ago and moved to Colorado soon afterwards.
Watts did not enter a plea to three first-degree murder charges, two counts of killing a child under 12, one count of unlawful termination of a pregnancy and three counts of tampering with a deceased human body, during his last court appearance on Monday.