A West Ashley car dealership reported 24 catalytic converters stolen over the weekend, continuing a trend that has plagued the Lowcountry and other regions as thieves seek out the car parts for their scrap value.

An exhaust-system component designed to reduce emissions, catalytic converters are coveted for precious metals inside and can be resold for up to $100 each.

Local businesses first reported a surge in converter thefts almost two years ago. To date, local authorities have announced no arrests.

A Morris Nissan employee told Charleston police that two dozen converters were taken from vehicles on the lot on 1714 Savannah Highway between Friday night and Monday morning. The devices had a combined value of $24,000 and were removed by cutting the exhaust pipe, a police report says.

Charleston crime-prevention Sgt. Trevor Shelor said the best defense against this type of crime is for a business to keep its property visible from the road. That way, others are more likely to notice if thieves are up to no good.

"We really need for passing citizens to take note if they see somebody walking through a parking lot, particularly at night, to call the police about it being suspicious," Shelor said.

A passerby is thought to have thwarted a catalytic converter theft in a back parking lot of Citadel Mall about a month ago by driving up to two men at a parked car. The men, one to the side of the parked car and the other underneath it, quickly got into another vehicle and left.

Shelor said car lots and businesses with fleet vehicles should consider keeping somebody on site whenever possible, as well as installing fences topped with razor wire.

Catalytic converters contain small amounts of platinum, rhodium and palladium. Once removed, they are hard to track. They have no protective shielding to prevent theft and no ID number to track them after the fact.

Morris Nissan wasn't the only business to be targeted recently. North Charleston police and other departments have fielded numerous reports, too.

Rodgers Enterprises, a car lot near Dorchester and Cross County roads, reported having three of the devices sawed from vehicles May 28-29.

A Goose Creek woman noticed the catalytic converter missing from her 2001 Toyota Tundra pickup after parking it at the Target store on 7250 Rivers Ave. on the night of May 23.

And 11 catalytic converters were stolen at Marathon Chevrolet on 8199 Rivers Ave. between the night of May 22 and the following morning.

Reach Noah Haglund at 937-5550 or nhaglund@postandcourier.com