The Replacement Killers (1998)

About the film: A professional killer John Lee gets a new assignment - to kill a police officer. But at the decisive moment, he was unable to press the trigger: the target was a child. A mob does not forgive mistakes. To replace it sends its people, and John becomes the target. Now he and moshennitsa Meg, which accidentally became a party to all the events that fall under the cross-fire of criminals and police. The only way to escape - and hiding from those and from others, but sooner or later they will have to confront face to face ...

See: The Replacement Killers at Wikipedia