Siren Call (2006)

Detectives Goren and Eames investigate the brutal murder of a teenage girl in The Hamptons, found dead in her car in Queens after a night of partying. The detectives probe the uneasy family relationships concerning the murdered teen's stepfather, a local police officer who has had to deal with his rebellious daughter, all the while trying to protect his youngest child and his dying wife. Nevertheless, the discovery of a cell phone records soon deflects the team's investigation in another direction, leading them to investigate her married boss, a supermodel's husband, who had maintained an extramarital affair for a long time with the victim. But when yet another supposed lover comes forward, their attention turns to a different source, while resistance from the local police complicates the investigation. Eventually its revealed that her step-father, a cop, murdered her because of the stress she was causing her dying mother who has cancer with her wild antics. Ultimately her killer decides to kill Goren and then himself, knowing that if he kills himself before he's charged, his wife will get his pension. Goren manages to disarm him, but as he's taken into custody, he grabs an officer's gun and kills himself in front of the police and his horrified family.