Running Scared (2006)

Joey Gazelle is a low-level mob flunkie whose role is to dispose of "hot" guns from mob killings. However Joey has been hiding these guns in his basement instead of tossing them into the river. When Joey's 10-year-old son and his best friend Oleg witness Joey hiding some guns from a botched drug deal, Oleg steals one of the guns and shoots his abusive stepfather. Things would be bad enough if the stepfather didn't happen to be the nephew of a psychotic Russian mob boss. But now Joey's also got the surviving dirty cop from the botched drug deal on his case.

Official website: http://www.runningscaredthemovie.com/