On the morning of October 12, 2015, neighbors on North Altadena Avenue in Royal Oak, Michigan, heard arguing followed by a loud boom. Officers responding to 911 calls found 50-year-old Theresa Diamos inside her home gravely wounded from a gunshot; she was alive at the scene but was pronounced dead after being taken to a local hospital.

Theresa’s live-in boyfriend, David Douglas Davis, was at the house and initially told police an intruder had shot her. A search turned up no evidence of a third person, and Davis’s account soon unraveled. He was arrested at the scene and charged with first-degree premeditated murder, two counts of possession of a firearm in the commission of a felony, and being a felon in possession of a firearm. Neighbors had reported hearing the couple arguing before the shot.

Davis was convicted by a jury and received a mandatory life sentence without the possibility of parole. During sentencing Theresa’s mother addressed him, confronting her grief while acknowledging he will spend the rest of his life in prison.

If anyone knew Theresa, her routine, or what happened that night, please come forward with information.