The Whole Nine Yards (2000)

"In the heart of suburbia, a hit man with heart has just moved in."

After a mobster agrees to cooperate with an FBI investigation in order to stay out of prison, he's relocated by the authorities to a life of suburban anonymity as part of a witness protection program. It's not long before a couple of his new neighbours figure out his true identity and come knocking to see if he'd be up for one more hit—suburban style.