The Butterfly Effect 3: Revelations

Sam Reide (Chris Carmack) witnesses a woman being killed, then wakes up in an ice-filled bathtub, his vitals being monitored by his sister Jenna (Rachel Miner). Sam can travel back to any time and location during his lifetime (occupying the body of that time in his life), needing only to concentrate on where and when he wishes to arrive. He has helped the local police capture criminals under the guise of being a psychic. Sam pays his sister Jenna's rent and buys her groceries, as she rarely leaves the apartment and lives in squalor.