Angel of Death (2003)

On the graveyard shift at a large, Southern California hospital, a shadowy figure prowls the halls, choosing which patients will live and which will die. Rumors of foul play go unheeded and unreported. A blackmail attempt and a surprise confession lead investigators on a two-year quest. Their only clues lie six feet underground, in bodies now resting for eternity. With the help of forensic science, detectives follow a trail of victims to a serial killer who calls himself "The Angel of Death."