Car part dealers and resellers must soon identify anyone looking to sell them second-hand catalytic converters, Denver City Council decided Monday, approving a law looking to cut into the black market for the often-stolen devices. Denver saw a nearly 900% increase in thefts of the emission control devices last year. Police say a talented thief can crawl under vehicles and steal a catalytic converter in less than 30 seconds and that the city is already on pace to break the record amount of thefts reported last year. The new law looks to the resale market in an attempt to reduce the amount of thefts.