Da Vinci's Inquest (1998) : 1x9

A noisy house party ends in tragedy when a fifteen-year-old teenager is found shot dead. Initially it looks like another death in a recent spate of teen suicides in Vancouver. Rumors soon start circulating around her school that she didn't fire the gun. As the teenagers close ranks Da Vinci, Leary, and Kosmo find it difficult to piece together a clear picture of the unpopular girl. The school counselor describes Jodie as an intelligent, hard-working loner, and a talented writer, whose only close friend was her sensitive, highly intense boyfriend Peter Florick. Jodie's brother, who owned the handgun, had previously warned Peter away from his sister and even Peter's classmates think he killed the girl. Troubled by his own ignorance of his teenage daughter Gabriella's friends and feelings, Da Vinci initiates a thorough investigation. The net tightens around Danny when a mobster's girlfriend, Summer, seems to be getting too close to Leon. It becomes suffocatingly tight when Leon confronts the undercover cop who has been tailing him.