Find out why James Henrikson had Doug Carlile fatally shot in his Washington state home, and how Henrickson was linked to Kristopher Clarke's disappearance.

Find out why Joseph O’Boyle brutally killed his doctor, beloved chiropractor James Sowa, in his Bensalem, Pennsylvania, home, and how detectives found him.

Learn more about the investigation into Michigan man Trent Mallory's 2014 murder, as told in Oxygen's Killer Relationship.

What happened to the Memphis businessman?

Season 3 Preview: "Trader Trent's" following on Facebook Marketplace opened up a range of possibilities for detectives.

Alex Sowa, Jim Sowa's son, tearfully recalls finding his father's body.

Detectives reveal the weather was vital in Trent Mallory’s case.

Investigators and loved ones speak out on Ezra McCandless's violent nature.

Preview: It is quickly discovered that Carmela Knight died from blunt-force trauma before being badly burned in a house fire.

Preview: Carmela Knight, a "suburban hockey mom", was found dead after a house fire surrounded by drug paraphernalia. What happened?

Friends and family tearfully recall the night that led to Carmela Knight's death.

Dr. Jim Sowa is killed by his patient, Joey O'Boyle, who had a history of violence and mental health struggles.