They have pictures of the man in the act captured by security cameras.
Three times they say he's made off with thousands of dollars worth of computer systems.
Then, on Thursday night he was back.
He damaged the office door, but this time, walked away empty handed.
"We moved up to very large chains and combination locks, which seemed kind of humorous, until you realize the situation we've been in where he's stolen between $35,000 and $40,000 worth of hardware and done several thousand dollars worth of damage," says Alex Ackerman from Diablo Publications.
Every time, the police always get there fast, but the burglar, so far, has been faster.