Neighbors, businesses and area police departments ask that residents be wary of a recent wave of catalytic converter thefts from cars. The devices, which control exhaust emissions from vehicles, can be sold to scrap yards for the trace amounts of precious metals they contain. âIn the past two months â December and January â we have taken a total of five reports for catalytic converter thefts,â said Lt. Andy Miller of the Webster Groves Police Department. âIn the three previous months, there had been four reports.â Miller said four of the recent thefts occurred at businesses, with three of those at an auto repair business. All incidents occurred in the overnight hours. Police believe thieves are using a cordless reciprocating saw in the thefts.Â