A San Diego thief learned the easy way that a dog isn't just man's best friend, but a crook's too ... as seen in this video.
Here's the deal ... SDPD is trying to catch this guy, who they say broke into someone's garage in the Pacific Beach neighborhood a couple weeks ago -- and then made off with one of their pricey bicycles that's valued at over $1,000.
The worst part, it seems, is that the family's pooch didn't do anything to help -- although, he did slow the burglar down. And by that, we mean he rolled over for some belly rubs.
Check it out -- this beach bum was about to walk away with the bike, but suddenly ... Fido comes running out to confront the man, seemingly determined to stop him. Just kidding -- he was mostly out to greet the stranger and to lick his face a bit ... and did exactly that.
The thief was quickly won over by the canine, who was only out for attention and scratches. Fortunately for the dog, this fella was willing to pause his caper for a little play time ... and while what he ultimately did was very wrong, it's pretty freakin' hilarious to see this.
Of course, San Diego cops aren't laughing -- and we're sure the family isn't either.