Although Watts denied the cheating allegations in conversations with police, authorities say their investigations have confirmed the affair with an unknown co-worker.
On closed internet forums about the case, four separate women have been identified as the possible woman involved – including women who reportedly worked alongside the couple as promoters for weight loss patch company Le-Vel.
Forensic profiler Dale Yeager has also suggested a number of motives that may have led Watts to allegedly murder his family.
“For Chris to [allegedly] make the leap from adultery to murder, 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 told Hollywood Life.
“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.”