The suspect, described as a slightly built Hispanic man in his 20s, managed to steal patrol car 2520 after he had been left in the back of the Chevrolet cruiser with his hands cuffed behind his back.

How the suspect took control of the vehicle will be the subject of an internal investigation, said Lt. Frank Vanore, the department spokesman. The suspect apparently slipped his cuffed hands under his feet and then squeezed through an opening in the Plexiglas panel separating the back and front seats.

The Plexiglas panel, which slides open, should have been locked, Vanore said. And department policy requires vehicles to be shut off when not attended, he said.

"I have a lot of questions about how that occurred, too," Vanore said. "Everyone involved will have to explain what happened."

The suspect had been arrested after a police pursuit from North Philadelphia to Center City.

It all began at 5:49 a.m. after someone flagged down a Philadelphia police car and told the officers that two armed men were driving around the area of North Second Street and West Glenwood Avenue, firing from a gold-colored Chevrolet Tahoe.

Police spotted the car and pursued it down Interstate 95 until the SUV exited the highway and crashed into a wall near Sixth and Wood Streets. Police said they found drugs, cash, and a few rounds of ammunition in the vehicle.

Police handcuffed and arrested both men, and put the SUV passenger in the back of Car 2520.

As investigators were working the scene, police said, the suspect fled in the cruiser, sped down Sixth Street and escaped over the Ben Franklin Bridge.

Police Commissioner Charles H. Ramsey said some suspects are agile enough to slip their handcuffed wrists behind their backs and under their feet. "It's highly unusual, obviously," he said. "We've got to figure out how he did it."

Vanore said the suspect apparently did not leave the backseat through the passenger doors, which are designed to be opened only from the outside.

Camden police found the abandoned police car within the hour at the Centennial Village Apartments in the 1200 block of East State Street. The vehicle had sustained damage on the front-right quarter panel.

The other suspect, 23, was being questioned but had not been charged.