DES MOINES, Iowa —  Pig fetuses believed stolen from a biology lab at a Des Moines high school were found impaled on car antennas at a rival school's parking lot in West Des Moines.

The incident was discovered on Tuesday at Dowling Catholic High School.

The pig fetuses were believed stolen from Roosevelt High School. They were on about 15 cars, along with a pound of biology-class crawfish that were smeared on hoods and windshields.

"You could smell the formaldehyde from a block away," Dowling Assistant Principal Ron Meyers said.

Roosevelt Principal Kathie Danielson said science teachers "can't be sure" the pigs came from Roosevelt. She said the pig fetuses aren't labeled and the school doesn't keep inventory.

"We certainly don't want issues with schools. We want good relationships," Danielson said. "I like to be trusting and hope any students who may have been involved will come forward."

Meyers said Dowling officials "have faith the parents will deal with their kids appropriately, and the school will too."

The incident wasn't reported to police, but a police officer assigned to Dowling contacted his counterpart at Roosevelt to investigate.