The Killing Jar (crime thriller)

The Killing Jar is a 2010 American crime thriller film written and directed by Mark Young. It stars Michael Madsen as a psychopath who takes the occupants of a remote diner hostage, only to realize that one of them is more dangerous than the gunman. Amber Benson stars as Noreen, a waitress at the Diner.
Plot
Several people are gathered at a diner—Noreen, a friendly and talkative waitress; Lonnie, a dim-witted cop; Jimmy, the short-tempered owner; Billy and Starr, a young couple on their way to elope; John, a meek salesman on his way to New York City; and Hank, a quiet regular. A radio is playing, and the group hears of an entire family murdered gruesomely in a neighboring county. Noreen, shocked, becomes increasingly agitated and nervous after an aggressive man in a black leather jacket enters. Noreen covertly asks Lonnie to investigate the newcomer, but Lonnie brushes aside her concerns. After Noreen spills the man's coffee, Hank urges Lonnie to do something.