Things We Lost in the Fire
(2007)

Audrey and Steven Burke are married with 2 kids (Halle Berry and David Duchovny). Steven is killed when he tries to stop a domestic dispute from happening in a parking lot. The husband shoots him for trying to help and then kills his own wife.

Jerry (Benicio Del Toro) is Steven's best friend, but has had a problem with heroin for years. Audrey helps him to get clean and he moves in with Audrey and her 2 kids, living in the garage. When things seem to be going ok, Jerry is clean, the kids love him, Audrey gets upset because she sees Jerry as taking Steven's place. She kicks him out and he goes back to using drugs. She finds him and nurses him back through the withdrawls. At the end Audrey and the kid see him off to rehab where he is going to get clean and then find an apartment.

Thanks Brian!