St. Paul police help residents mark catalytic converters as theft of car parts becomes rampant article Police held an event Saturday to allow car owners to get their catalytic converters marked -- with hopes it will dissuade theft. (FOX 9) ST. PAUL, Minn. (FOX 9) - As the theft of catalytic converts from vehicles is becoming a bigger problem in the city, St. Paul police are taking steps to dissuade thieves. "It was just an ungodly loud and it did not sound healthy," Spencer John said of a noise that is unfortunately becoming all too familiar; the sounds from a car’s engine after a thief has stolen its catalytic converter; for the valuable metals inside.