The Plano Police Department is tracking an increase in thefts of catalytic converters, the emission-control devices used to convert toxic materials in a vehicle's exhaust to less harmful chemicals.
Catalytic converters are a hot item for thieves as they contain metals that they then scrap and sell for cash.
Police say overall, the number of thefts in Plano has decreased as the prices dealers pay for scrap metal have decreased.
However, they have noticed an increase in catalytic converter thefts from vehicles parked in high school parking lots.
The department says the vehicles that are most commonly targeted are Toyota trucks and SUVs, plus Mitsubishi Outlanders.
Car owners are being urged to take some steps to help prevent thefts, including installing anti-theft devices, painting the converter orange, and etching their VIN or other information onto the converter.
Vehicle owners are also advised to park in well-lit areas and install motion-activated lights or cameras at their homes.
Plano Police are also asking people to stay vigilant in school parking lots and to report any suspicious behavior.
They say power tools are used to remove catalytic converters, so a loud cutting noise could mean that thieves are at work. They say those criminals are frequently armed, so they recommend against trying to confront them - and say people should instead call 911.