The thefts occurred during a four-day period starting July 23, according to a police report filed by an employee of Student Transportation of America. All 12 of the catalytic converters, valued at $1,500 each, were taken from buses parked at a company lot near 85th Street and Crown Point Avenue in northwest Omaha. 

A catalytic converter is an emission control device that can cost up to $3,000 to replace. Each catalytic converter contains small amounts of valuable metals such as platinum, palladium or rhodium and can command large sums as scrap metal.

Thefts of catalytic converters are a nationwide problem that seems to spike when prices of rare metals go up, according to an Omaha police spokesman. Businesses where thieves can move rapidly from vehicle to vehicle often are targeted.

Police said it can take as little as 30 seconds for a thief to roll under a vehicle with a power saw, make cuts on each end of the converter and get away.