Anyone remember this movie?

This is driving me crazy. All I remember is that a guy got into a situation where he had to make up a story to his girlfriend. He claimed to be mugged and gave her a crazy random description to give to the police. Then the police call and say they think they got the guy. They go to the police station and turns out, they found a guy that fits the crazy description the guy gave his girlfriend. I want to say the girlfriend was played by selma blair, but i'm not sure. Any guesses?