Officer John Moynihan, 34, was in critical condition at Boston Medical Center late Friday after a gang unit stop turned violent, authorities said. The officer was “fighting for his life,” Commissioner William B. Evans said.

A Boston police officer credited with helping to save a Transit officer wounded in the Watertown shootout with the Boston Marathon bombers was himself shot in the face Friday night in a Roxbury confrontation that left a suspect dead and a bystander injured.

Officials were at the scene of the shooting in Roxbury at Ruthven Street and Humbolt Avenue Friday.

In April 2013, Moynihan was among those who assisted Transit police officer Richard H. Donohue Jr., who was shot and bleeding heavily amid a shootout with Tamerlan and Dzhokhar Tsarnaev days after the Marathon bombings, said Lieutenant Michael P. McCarthy of the Boston police.


Moynihan was later honored by President Obama with a Top Cop Award at the White House.

Friday’s incident began at 6:40 p.m. when gang unit officers investigating a report of shots fired stopped a vehicle on Humboldt Avenue near Crawford Street to interview its three male occupants, authorities said Friday night.

The suspect stepped out and began to flee while firing his gun, said David Procopio, a spokesman for the State Police, which works alongside Boston police to address gang violence.

The suspect wounded Moynihan under the right eye, Evans said.

A law enforcement official also said the suspect, who was not identified, had several previous gun-related charges.

Evans said that the stop was initially routine and that the suspect had fired at police “before they had time to react,” but the officers quickly returned fire, killing the suspect.

Gunfire also struck “a middle-aged woman” who suffered a flesh wound, possibly in her right arm, Evans said.

“I think she got caught up in the crossfire,” he said.

Evans, who did not identify Moynihan as the officer involved, said he was a “highly decorated military veteran” and “one of our most outstanding officers in the Youth Violence Task Force,” commonly known as the gang unit.


A law enforcement official said that, in addition to helping to save Donohue, Moynihan was active at the Boston Marathon finish line in the aftermath of the bombings, helping to triage the wounded.

The official said Moynihan is “the absolute best type of soldier and police officer” and is “selfless, courageous, and giving.”

The officer’s family was with him at BMC, along with clergy, Evans said.

Three other police officers involved in the incident were taken to Brigham and Women’s Hospital for stress, according to Evans. Police were interviewing two other occupants of the car.

“You’ve got way too many guns out there and way too many young kids running around with the guns, and unfortunately this is what happens,” Evans said.

Mayor Martin J. Walsh said in a statement that his thoughts and prayers were with the officer, his family and friends, and the Police Department.

“These acts of violence have no place in our neighborhoods,” Walsh said. “Our community is stronger than ever, and tonight we are thankful for all of those who put their lives on the line every day to protect our city.”

A Boston police officer was last shot on Dec. 7, 2013, according to Officer Stephen McNulty, a department spokesman. In that incident, alleged gang member Darryl Dookhran, 20, opened fire on two plainclothes officers near Geneva Avenue in Dorchester, wounding one of them in the arm, before the officers shot and killed Dookhran, police said at the time.


Friday’s shooting took place just feet from the site where, in August 1988, 12-year-old Darlene Tiffany Moore was fatally struck by stray bullets fired by feuding drug dealers.

At the scene on Friday, crime tape blocked off two or three blocks in every direction, and police vehicles were scattered on the streets.

A helicopter circled overhead, and one police officer could be seen walking away with small boxes labeled “evidence.”

Rajon Porter, 37, who lives on the corner of Humboldt and Crawford, said he was asleep when the shooting happened. At least 20 gunshots woke him, he said.

Porter said the neighborhood is a “high crime” area, with gangs and frequent shootings.

He hopes to move soon, he said.

Michelle Williams, 36, of Mattapan, was visiting a friend when she thought she heard thunder. “I heard a lot of it,” she said.

Williams said she decided to go outside when she heard sirens. “I was like, ‘What is going on?’ ” she said. “I’m not used to this.”

At Empanada’s House, a restaurant at the corner of Humboldt and Ruthven Street, people said they had heard multiple gunshots.

“Around 12 or 10. Really, really bad,” said Luisa Hollman, by phone. She said the business was effectively put on lock-down. “We can’t get out and nobody can get in,” she said.

A brief scuffle broke out at the scene about 9:30 p.m., when a group that appeared to be upset over the shooting began shouting and swearing at police. Shoving broke out as police moved the yellow tape back.


Kay Lazar, Sean P. Murphy, and Maria Cramer of the Globe staff and Globe correspondent M.G. Lee contributed to this report. Jeremy C. Fox can be reached at jeremy.fox@globe.com. Melissa Hanson can be reached at melissa.hanson@globe.com. Evan Allen can be reached at evan.allen@globe.com.