Killer Relationship with Faith Jenkins is taking on one of its toughest cases involving polygamy and religion.

The upcoming episode, “Forbidden Love, Brutal Death,” follows the tragedy of a woman who was part of a polygamous marriage. According to the logline, “Two unlikely lovers form a secret bond held together by faith, but the polygamous marriage festers until a manipulative and deceitful charlatan kills the woman he once loved, a beautiful young mother of two sons.”

The woman, Joy Risker, thought she had found love with youth pastor Sean Goff, whom she met in church. According to the Oxygen True Crime page, She disappeared Sept. 2003 after she and her husband had dinner. Goff told friends and family that Risker left him and their kids for an old boyfriend and produced emails to make it look like they had planned the escape. But it was eventually discovered by that the emails were made on the same computer. Her mutilated body was found three months later in the desert of Arizona.

Watch the exclusive clip from the episode below.

Killer Relationship brings viewers on the journey of some of America’s most notorious true crime stories of love gone wrong. According to the description:

Killer Relationship with Faith Jenkins investigates burgeoning romances from their sweet beginnings, and follows what happened all the way through to their bitter endings. With her background as a criminal prosecutor in the Manhattan District Attorney’s Office, and with her expertise in matters of the heart, Faith Jenkins gives her professional POV of the nightmarish cases. With first-hand accounts from victims’ family, friends and law enforcement, each hour-long episode reveals the inner workings of intimate attachments that seemed fated to last forever and ended in murder.

Killer Relationship with Faith Jenkins airs Sunday at 7/6c on Oxygen.