When some copper wire turned up missing in Glendale, Arizona, the cops didn't have to dust for prints, they had the idiots finger tip to use for clues. Yeah, they caught him.

Early last month, 29-year-old Joshua Goverman of Glendale, Arizona tried to steal some copper wiring off an air conditioner repairman's truck.

Joshua got some wire . . . but also SLICED off the tip of his left ring finger when the wiring got tangled around his hand.  He took off with about $300 worth of wire . . . and WITHOUT his fingertip.

And as the cops were investigating the robbery, they found the fingertip.  Then they were able to pull his fingerprint off it, and track him down.

When they looked him up on Facebook, he'd actually posted PHOTOS without his fingertip.  He wrote, quote, "Got it caught in fan belt of car while helping my friend."

That obviously wasn't true . . . and he was just arrested for theft.