Congressional Candidate Arrested for.....What Exactly?

San Diego- Ray Lutz, a Democratic congressional candidate, was arrested by the San Diego Police Department for...something.  He says it's for registering voters and the police claim it's because he was "trespassing and refusing to leave," or something.  After his arrest more than 30 people were registered thanks to other activists who weren't arrested.  Now Lutz is suing the police for the action.  Here is the video.