The three suspects in the traffic-stop shooting of two New York City police officers may have been behind other brazen crimes using the same illegal weapons originally purchased at gun stores in three southern states, authorities said Thursday.

The crimes include a drive-by shooting that, like the police shooting, involved a luxury car taken from a dealership where one of the men was a salesman.

Investigators were re-examining unsolved robberies and shootings over several months to see whether the suspects were involved “individually or collectively,” Police Commissioner Raymond Kelly said.

Pennsylvania state troopers caught one of the suspects early Thursday morning along a wooded stretch of Interstate 80 where police said he spent the night hiding with a 16-ounce jar of peanut butter. His capture ended an intense, three-day manhunt in the Pocono Mountains sparked by a shooting that left one of the officers gravely wounded.

A New York Police Department bloodhound named Scooby helped corner Robert J. Ellis before he was caught by state troopers, police said. He and another suspect captured near the same spot on Wednesday, Dexter Bostic, were ordered extradited to New York at a hearing Thursday in Stroudsburg, Pa. Formal charges were pending, though police said the men would face attempted murder and other counts.

At the brief extradition hearing, Dexter wore a blue T-shirt, faded baggy jeans and sneakers — the same outfit, police said, he was wearing the morning of the shooting. Afterward, the handcuffed suspects bowed their heads and ignored reporters’ questions as they were led to two unmarked police cars.

Authorities allege Bostic and Ellis, both 34-year-old ex-convicts, were riding in a stolen SUV driven by a third man, Lee Woods, when it was pulled over by police early Monday morning in Brooklyn. As officers Herman Yan and Russel Timoshenko approached either side of the vehicle, Bostic shot Mr. Timoshenko in the face with a .45-caliber pistol and Ellis fired on Mr. Yan with a 9mm semiautomatic handgun, police said.

A third gun — a Tec-9 pistol with a 24-round magazine — was being loaded by Woods at the time, but wasn’t fired, according to a criminal complaint charging Woods with attempted murder. The stolen BMW sport utility vehicle and the three guns were ditched a few blocks away.

Woods’ lawyer, Patrick Michael Magaro, said there was nothing in the complaint to suggest that his client intended to harm the officers.

A Pennsylvania public defender representing Ellis and Bostic at the extradition hearing said they were willing to return to New York to face charges. It was unclear if either had hired lawyers in the city.

Mr. Timoshenko, 23, remained in extremely critical condition on Thursday; Mr. Yan, saved by his bullet-resistant vest, was released from the hospital Tuesday. In a symbolic gesture, police said the officers’ handcuffs were used on Bostic and Ellis after their capture.

Police and federal agents tracing the origins of the guns involved in the shooting learned that the .45-caliber pistol was originally purchased in Virginia, the 9mm semiautomatic in Alabama and the Tec-9 in Tennessee, a law enforcement official who spoke on condition of anonymity, said.

Spokesman for the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, Joseph Green, said one of the pistols was first purchased around a decade ago and had apparently changed hands at least twice previously. Another gun was bought within the past year, he said, raising a possibility that investigators might be able to find the person who sold it to the shooter.

Ballistics evidence showed that the .45-caliber pistol used in the shooting of the police officers also was used a day earlier in a drive-by shooting in Queens, police said.

The shooter was in a Porsche that was taken from a car dealership on Long Island, then returned after the crime. It was the same lot where the SUV was stolen and where Bostic had worked.

Police also were investigating whether any of the weapons were used in the unsolved slaying earlier this year of a salesman at another, nearby Long Island dealership. The 27-year-old victim was shot in the back at closing time.

“The capture of the last suspect in the shootings of our police officers has provided some relief in the otherwise grim reality that Officer Timoshenko remains gravely wounded,” Mr. Kelly said Thursday.

Police say the suspects initially evaded them with the help of an unidentified man who agreed to drive them from Queens to the Poconos several hours after the shooting.

Fearing they would be captured if they drove through New York City, they fled east into Long Island before taking a ferry to Connecticut, then northeast back through New York to Pennsylvania.