When a police officer is found dead in her home with a bullet between her eyes, who investigates?

Both Ciara Estrada and her boyfriend were San Diego police officers. They went with friends to a New Year’s Eve party. Pictures from that night show the smiling couple. The next day, Ciara was dead … discovered on her bathroom floor with her gun in her lap.

Her own department investigated the death and quickly ruled it a suicide. Investigators, who were her colleagues, made no arrests. Identified no suspects.

But her family says there’s more to her story – tragic circumstances that should have prompted a more thorough investigation. They don’t think the police dug deep enough into the death of one of their own.

EDITORS' NOTE: A previous version of this episode incorrectly stated which of Ciara Estrada’s guns was in her lap when police found her dead.

A San Diego Police officer went viral in 2016 for being “Finally, a NICE cop.” A video of her talking respectfully to a panhandler received more attention than her sudden and complicated death less than two years later. But who was Ciara Estrada?

EDITORS' NOTE: A previous version of this episode incorrectly stated which of Ciara Estrada’s guns was in her lap when police found her dead.

Ciara’s family blames her death on her relationship with her boyfriend, who was also a San Diego Police officer. What is the line between an unhealthy relationship and an abusive one? Do police departments have a responsibility to address toxic relationships within their ranks, even when they leave no marks?