"They slide under a car and they're out within 30 seconds," says Sergeant David DiTrolio.
Now it's up to Sgt. David DiTrolio and the Springfield Township Police Department in Delaware County to catch these thieves snatching catalytic converters.
It's believed five cars were hit within a few blocks, all happening on the night of November 24. Reports started to come in as people started to come out to their cars, police said.
"The person came out, started the car, and of course, listened to the loud noise that the catalytic converter muffles and realized the converter was missing," says DiTrolio.
It's a frustrating reality for drivers. Any sitting vehicle may become a target.
"I do the best I can in my house. I have lights on. I keep the car locked, but I can't watch the car 24/7. It's a shame," said Mike Part of Clifton Heights.
"I have family that lives in Springfield so I worry about that," says Kate O'Neill of Broomall.
Why do thieves steal converters? Valuable parts inside can bring in quick cash.
"Precious metals that can be sold for value. And of course, there's ways going into these shops to find who is selling these things," said DiTrolio.
Springfield Township police say detectives are combing through surveillance video to catch the person or people responsible for the latest string of thefts.