A threesome started on a dating app turned deadly after one woman's boyfriend showed up.

Heidi Kathleen Carter's boyfriend Carey Hammond came home and saw Carter, one man and one woman having sexual relations.

He became angry and started beating the male victim.

This is where things get even more twisted.

Heidi, 36, and Carey then restrained both victims with duct tape and abused them for hours. Carey killed the male victim by strangling him with a belt.

The female victim was hospitalized, but her condition is not known yet.

The police shot Carey Hammond while Heidi was facing murder and rape charges.

The tragedy in Evansville happened in an unnamed man's home. He told the police:

"Heidi was staying there until she could get on her feet, her boyfriend Carey started coming over, and things got bad with them fighting a lot. I had asked her not to have anyone over because of my kids, but [she] obviously didn't listen."

The man was at work while the couple was abusing and torturing its victims. His two teenagers did not hear anything and were not harmed during this horrific incident.

Evansville Police Sgt. Anna Gray stated:

"The entire situation — from the first responding officer who was flagged down [and told] there was a dead body in this house … [to others] finding a victim who was tied up and beaten — it took officers by surprise."

Carter has a criminal record, as she was arrested for battery, resisting arrest, giving false police statements, theft, disorderly conduct, and criminal mischief. She is currently jailed without bond.