"I've never heard of anyone stealing two police cars in the same incident," said Philadelphia Deputy Police Commissioner Richard Ross.
Philadelphia police eventually arrested Blake Bills, 24, and Shayna Sykes, 23, of Macungie, Pa., and charged them with offenses including driving under the influence, resisting arrest and risking a catastrophe.
They had recently been reported missing by a relative, Ross said, adding that drugs were likely involved in the case. The couple has a 7-month-old child, he noted.
The drama began unfolding across the Delaware River in Camden, N.J., around 10 a.m. after an officer made an unrelated traffic stop outside police headquarters, authorities said.
When the officer left his marked car running to talk with the motorist, Bills and Sykes happened to be walking by and jumped in the cruiser, police said. As they drove off, they struck the 16-year member of the force, who is now hospitalized with a broken leg, authorities said.
Bills then led police from several jurisdictions on a chase through neighboring Pennsauken and Cherry Hill before turning back through Camden at speeds estimated at 100 mph, officials said.
He then crossed the Ben Franklin Bridge into Pennsylvania, where local police caught up with the damaged patrol car in north Philadelphia. Bills was taken into custody, but Sykes managed to escape and commandeer an unattended Philadelphia cruiser, officials said.
She then led police on a second, shorter chase in which she hit several vehicles before coming to a stop in the city's Northern Liberties neighborhood, possibly because the cruiser was so badly damaged, Ross said. Police subdued her as she tried to flee.
Ross said he didn't fault the Philadelphia officer for leaving his car running to assist colleagues with volatile suspects about whom little was known.
"You only know that somebody was bold enough to do something that crazy," Ross said.
Macungie Police Chief Ed Harry said in an email that the couple had borrowed a car belonging to Sykes' grandmother on Friday afternoon.
When they hadn't returned by Monday morning, she reported the pair missing and the car stolen, Harry said. Macungie is about 45 miles northwest of Philadelphia.
Bills and Sykes are considered suspects in an attempted carjacking Tuesday in Camden just before the patrol car was taken, said Jason Laughlin, a spokesman for the Camden County Prosecutor's Office.
They're also being looked at as suspects in a police pursuit in Camden on Sunday related to a suspected drug purchase, said Laughlin. Those suspects were never caught, he said.
Philadelphia police said Bills and Sykes will be extradited to New Jersey, where authorities were preparing to file charges against them including aggravated assault and theft.
It wasn't immediately clear if the couple had a lawyer.