A homeless guy robbed a house in Seattle and got busted… thanks to the dirty underwear he left behind.

He broke in and took an iPod, digital camera, and a laptop. He also used the robbery to get a change of clothes.

He grabbed a set of clean duds and left his dirty ones behind.

Cops sent the clothes to the lab asking to get DNA from the undies to try to catch the crook.

They got a DNA lock on a guy, and it turns out, he’s already in jail for another burglary.