Help! Which movie was it where...?

This has been bugging me all day. I figured I might be able to get some help here, as fans of a show like SOPRANOS would know. Trying to find out the title of a movie that I've only seen bits from. Details are extremely hazy, however, I do know a few things...

- It was released within the past 15 years.
- In the opening scene an old man meets up with another old man and kills him. This happens in a public place... Wanna say a train station, but I can't be sure.
- The rest of the film is told in flashback in which the shooter is being interrogated by the police.
- Again, I can't be too sure, but I wanna say the shooter was a Holocaust survivor and the man killed was once the shooter's Nazi capture. Not certain on this though.

I know this is a long shot, but thought I'd check anyway. It's been killing me trying to remember.