If your position is of enough importance, then the interviewer probably already know you enough. Otherwise your position is probably not of enough importance and no one will bother to check references.
OK now for the "engineer" view.
If you read enough news, you will SEE some ex-con got back to working and steal AGAIN!! Then the company will say they duno, hmmmmmmmm. Really?!?!
So you think they check?
Trust me i am an "engineer".