The theft of parts from nearly 20 vehicles in Northwest Roanoke was reported last week, according to police.

Police spokeswoman Aisha Johnson said catalytic converters were cut from four vehicles Aug. 16 at S.C. Rossi & Co. in the 1400 block of 16th Street. The incident, which police believe took place between 4:30 and 5 a.m., was reported Aug. 18.

On Aug. 20, Johnson said, officers responded to Shenandoah Auto Parts in the 1900 block of Shenandoah Avenue, about a mile south of 16th Street. Initially police believed nine catalytic converters had been stolen from vehicles on the property, but it was later determined that 15 converters had been taken from scrap vehicles and a company truck.

John Walrond, who owns Shenandoah Auto Parts, estimated his loss at about $1,500.

It remains unclear when the Shenandoah Avenue theft took place, but Walrond said he believes it probably happened during the weekend of Aug. 16.

Police have not said if they know whether the two incidents are connected.

Catalytic converters, which reduce the toxicity of emissions, are often the target of thieves because they contain platinum. Victims are sometimes unaware that their vehicle has been targeted, but vehicles that have had their converters removed sound louder than normal. It is illegal to operate a vehicle that is not equipped with a catalytic converter.

Walrond said it is hard to tell if a converter is missing unless people look underneath vehicles.

He said some scrap yards buy the converters, but he believes the thieves probably sold them out of town. This week he posted an offer of $500 for information leading to the arrest and conviction of the thieves.