A thief who broke into a decoy car was caught out due to an "anti-crime" dye that turned his face bright green.
Yafet Askale, 28, was sprayed with the substance, which can only be seen under ultraviolet light, when he broke into a police "trap car" in Harlesden, north-west London.
Askale denied the charge of theft from a motor vehicle, but was convicted at Hendon Magistrates' Court.
Police said that the dye proved Askale had been in the car.
He was also found to have a number of stolen items, including a laptop.
Askale, of Harlesden Gardens, Harlesden, was sentenced on Friday to 49 hours of community service and was ordered to pay £400 costs.
Brent Police said they had also been providing residents with invisible dye kits so they can mark their property to deter thieves.