BOSTON (CBS) – He was allowed to shield his face in court, but prosecutors say 21-year-old Ernest Watkins, a man with a violent history, allegedly ran from the scene of a deadly officer involved shooting in Dorchester Monday.

His arrest is a relief to neighbors who feared retaliation. “When something like that happens, you don’t know if it’s the end of it or something else will follow,” said Dorchester resident Kathleen Wilson who lives near the shooting scene.

Prosecutors say Watkins, wearing a white tee shirt, was with a 19-year-old wearing a red shirt firing shots side by side into Town Field, and running when police came on the scene.

It was 19-year-old Jaymil Ellerbe, they say, who fired at officers in pursuit with a .357 magnum revolver recovered at the scene on nearby Penhallow Street. Officers returned fire, killing Ellerbe, but only after witnesses say they heard commands. “They heard multiple commands by Boston Police officers to drop the gun, prior to gunshots being fired,” said Suffolk assistant district attorney David McGowan.

Surveillance cameras in the neighborhood allegedly caught Watkins walking up a driveway near the shooting scene and walking a half mile to his house. He was convicted in 2015 of involuntary manslaughter for a fatal stabbing and sentenced up to five years.

On Monday, police say he was armed with a 9 mm pistol that has not been recovered. His defense attorney argued it could be a case of mistaken identity. “It’s troubling to know how many young males there are walking around a neighborhood wearing a white tee shirt in the middle of the summer,” said Chris Malcolm.

Prosecutors say a man was injured in Town Field Monday, not by bullets but as he ran from the gunfire. Watkins was picked up by police on several charges including illegally possessing a firearm and ammunition. He’s being held on $25,000 bail.

Beth Germano