There have been two recent thefts of catalytic converters from cars parked at residences in Atherton, police reported Monday, March 22. Thefts of catalytic converters are on the rise in the area and across the country, police said in a news bulletin.

Someone reported one stolen from James Avenue over the weekend, according to the town's crime blotter.

Stricter car emissions rules worldwide have increased demand for the precious metals in catalytic converters, leading to an increase in black market sales of the parts, police said. Some of the precious metals used in the device, such as palladium and rhodium, are at record high prices. (For example, rhodium, hit nearly $30,000 per ounce in early March, a 3,000% increase from about $640 an ounce five years ago, according to Trading Economics, a website that collects official records of commodity prices.)

Catalytic converters can be sawed off from the belly of a car in minutes. They can be sold for several hundred dollars at a scrapyard, which then sells the converters to recyclers who extract the metals, police said.

Residents should keep their cars in a garage, behind a gate, if possible, or in a well-lit area, to help deter thieves, police said. Residents can also install catalytic converter metal anti-theft guards.

It can cost up to $2,000 to replace a catalytic converter, and it is illegal to drive a car without one, according to Allstate Insurance.

Some states now require scrapyards and other recyclers to check photo IDs of those selling catalytic converters, police said. California requires businesses to take a photograph or video of the seller and retain that record for two years. But rules differ between states, which makes tracking and enforcement almost impossible, according to police.