AKA a Way with Murder (2003)

Producer Allison Tripp wakes up dazed and confused in an LAPD safe house. When Detective Mark Janus asks her about the dead bodies found in a Los Angeles warehouse she begins to remember... they had been shooting an ultra-low budget movie for infamous producer Ozzie Felcher when men with guns had come by and massacred the entire cast and crew. Janus is relentless in his questioning. He wants to know everything, before the trail to the killers gets cold. The more she talks the more she is forced to relive the nightmare.