A woman in Iowa has an unusual hero to thank for a thwarted mugging Thursday — a parked car.

Karla Gierstors was walking in downtown Des Moines at 6:15 a.m. Thursday when a man threatened her with a box cutter and nabbed her purse.

Hearing Gierstors scream a passing motorist then pulled over to help, and the thief, still looking back at Gierstors, ran smack into the parked car, the Des Moines Register reported.

The would-be mugger crashed so hard, he not only dropped the purse and the box cutter, but also did some damage to the side and trunk of the vehicle, according to the paper.

He still managed to get away but the purse was left behind, along with all its contents.

According to the Register, police are still looking for the inevitably bruised bandit.

Click here to read more at the Desmoinesregister.com.

The Associated Press contributed to this report.