Fairfax Police Chief Col. Edwin C. Roessler Jr. told members of the media Tuesday that escaped prisoner Wossen Assaye, 42, had been apprehended. U.S. Marshal for the Eastern District of Virginia Robert Mathieson described how Assaye managed to overpower a female contract security officer and escape. (WUSA9)

The prisoner was suspected of robbing 12 banks and getting away on a bicycle, but his escape from Inova Fairfax Hospital on Tuesday morning would prove even more improbable.

When a guard took a bathroom break, Wossen Assaye, a federal prisoner, somehow slipped his shackles and overpowered a second guard, taking her gun and using her as a human shield, authorities said. Assaye was being treated because of a suicide attempt, they said.

Assaye, 42, then fled his room in a hospital gown as the first guard fired a shot at him, authorities said. He scampered down a hallway without shoes, plunged down a stairwell and ran into the surrounding Fairfax County neighborhood.

The escape touched off a nine-hour manhunt involving hundreds of officers, dogs and a helicopter. Assaye allegedly carjacked two vehicles as police searched for him across Fairfax County and then in the District, where he was captured after being spotted on a Metro bus. Police said it was fortunate that no one was seriously injured.

“An alert community member identified Mr. Assaye,” Fairfax Police Chief Edwin C. Roessler Jr. said.

The escape spurred questions about how the U.S. Marshals Service secures prisoners who are receiving medical treatment at hospitals. Officials said the agency, which uses a private security firm to guard patients, would review its procedures.

The incident began about 3 a.m. Tuesday and led to a lockdown of the sprawling hospital complex in the Falls Church area of Fairfax County for nearly five hours, police said. Hospital officials said some surgeries were delayed. Officials also closed roads around the hospital, snarling the morning rush there.

After escaping from the hospital, Roessler said Assaye went to an apartment complex with the gun in hand. He broke into the trunk of a silver Toyota Camry and hid there until someone got in the car and left for work.

Roessler said that Assaye kicked through the back seat of the moving car and that the Camry crashed. Assaye then carjacked the vehicle and drove off, apparently with the driver still inside.

Preston Hall, who lives about 3.5 miles from the hospital, said he awoke to the sound of a massive crash outside his home at Cindy Lane and Backlick Road in Annandale.

Hall said a light-colored car had plowed into two vehicles in his driveway and was slowly backing away with a door ajar. He said he could see a woman inside.

“She was screaming bloody murder,” Hall said. “She jumped out of the car and took off running, and the driver sped off.”

About 10:30 a.m., Fairfax police found the car abandoned near Monterey Drive and Oak Court in Annandale. Officers, some in fatigues, swarmed the neighborhood as a helicopter flew overhead. The gun was found inside the Camry.

A short time earlier Assaye was seen fleeing through nearby woods, and then he carjacked a second vehicle, a Hyundai Elantra, police said.

Don Williams, who was working nearby on a landscaping job, saw a homeowner on Cherry Lane run in front of a car, yelling, “My car is getting stolen!” The homeowner, Williams said, jumped out of the way and was nearly hit by the car before it sped away.

Police said that Assaye’s movements after leaving Annandale were unclear but that a private citizen spotted him on a Metro bus near Minnesota Avenue and 25th Street SE in the District about 11:30 a.m. and alerted authorities. Assaye was captured without incident as he walked nearby.

At some point during the morning, he had changed into a dark jacket and blue jeans. It was unclear where he got the clothes, police said. They said the second car was later found in the District.

The suspect is known by police as the “Bicycle Bandit” and had been charged by federal authorities in one bank robbery, although he was suspected in 11 others in Northern Virginia.

Assaye’s mother — Hari Assaye who lives in Fairfax — cried during an interview Tuesday, saying her son had been on drugs. She said she last talked to him last week when he was being held at a jail in Alexandria.

“I told him, ‘God doesn’t give up on you,’ ” she said. She said her son appeared to listen to her.

Officials in the Alexandria Sheriff’s Office said Assaye was arrested March 20 and booked into the William G. Truesdale Adult Detention Center in Alexandria on federal charges.

Assaye was taken to Inova Fairfax on Friday after he put a bedsheet around his neck and dived off one of the tiers of the Alexandria jail, authorities said. He suffered a broken nose.

Under an agreement with the Marshals Service, federal prisoners are held at the Alexandria detention center, according to Amy Bertsch, a spokeswoman for the Alexandria Sheriff’s Office. Bertsch said sheriff’s deputies remained with Assaye until Saturday afternoon and then turned him over to security officers under contract with the Marshals Service.

Robert W. “Bobby” Mathieson, U.S. marshal for the Eastern District of Virginia, said it has been agency policy to have private security firms, not the Marshals Service, guard prisoners being treated at hospitals.

Federal records show that in January 2014, Allied Protection Services was awarded a contract with the Marshals Service to provide armed guards for work in the Eastern District of Virginia. The contract is reviewed annually but would be worth a total of $306,000 over five years.

The contract says a minimum of two armed guards are required when transporting prisoners and details a list of tasks they can be called on to perform when an inmate needs medical care at a hospital or doctor’s office and when moving within a health-care facility.

Fairfax County Supervisor Penelope A. Gross (D-Mason), who is also an Inova board member, said the escape was worrying. “I think that this probably gives us the opportunity to look at how security is provided,” Gross said. “There are plenty of prisoners that do require medical treatment at our local hospitals.”

Mathieson promised a full review of the escape, including whether the security guards followed protocols. Officials with Los Angeles-based Allied referred all questions to the Marshals Service.

Assaye has been charged with escaping federal officials, according to charging documents. Roessler said additional charges are also likely for the carjackings.

In a brief appearance in federal court Tuesday afternoon, Assaye — wearing a white jumpsuit, his hands cuffed and legs shackled — conferred frequently with a defense attorney but said little more than “Yes, sir,” in response to a judge’s questions. He was not wearing shoes.

He was closely flanked by four federal marshals, two of whom held his arms as they led him stumbling into the courtroom in Alexandria. Two other marshals sat in the courtroom.

Some of Assaye's answers were nearly inaudible, and at one point, he seemed not to answer at all. That prompted his defense attorney, Brooke Sealy Rupert, to ask Magistrate Judge Ivan D. Davis for a moment. After she conferred with Assaye, Davis repeated the question, and Assaye responded. Assaye was being held without bond. Rupert declined to comment after the hearing.

Emily Williams, Assaye’s fiancee, said in an interview during Assaye’s flight that she was “extremely concerned” about his well-being. She said she met Assaye, originally from Ethiopia, about two years ago at a 7-Eleven store.

“I love him with all my life, and I would die for him,” Williams said. But, she said later, in somewhat broken English: “He needs to go to the psych unit so he understands what he are doing is not what he’s used to doing. It’s not what he ought to be doing.”

Alice Crites, Mary Pat Flaherty, Peter Hermann and Jennifer Jenkins contributed to this report.