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

The 2013 slaying of a beloved businessman in Washington state helped federal officials not just uncover another man’s disappearance some 800 miles away, but led them to a group of violent men ...

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

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

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

What happened to the Memphis businessman?

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

Investigators find a partially packed suitcase in Joey O'Boyle's home.

After Uloma Curry-Walker's frantic 911 call, firefighters on the scene recognize Lt. William Walker, a fellow firefighter.

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.

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