PHILADELPHIA (AP/NewsNation) — Philadelphia police announced two people were arrested in connection with the Saturday shooting that left three dead and 11 more hurt.

Monday evening, they announced the second arrest was made by the U.S. Marshals Service, but did not reveal any other details. Earlier, Philadelphia police confirmed they’d arrested Quran Garner.

Police officers patrolling the South Street area in central Philadelphia at about 11:30 p.m. Saturday raced to the scene after hearing multiple shots and found several people with gunshot wounds lying on the sidewalk and in the street. Seeing a man on a corner firing a handgun at people about half a block away, one officer opened fire, and that man dropped his handgun onto the sidewalk and fled, authorities said.

Assistant District Attorney Joanne Pescatore said authorities have identified that man as Garner, and he faces multiple charges including aggravated assault and aggravated assault on law enforcement officers.

Authorities have said the gunfire started with a physical altercation between two people, both of whom then fired a total of 17 shots at each other. One man, 34-year-old Gregory Jackson, was killed and the other was wounded; no charges are planned against him since both men had permits to carry and that shooting is considered self-defense. A man who was with Jackson at the time of the altercation is the other person sought.

Police said Garner then began firing back at the area of the initial confrontation until he was wounded in the hand by fire from the police officer. He fled and surrendered to other police officers at the scene of an earlier shooting nearby.

Authorities have said that the other two people killed by the gunfire, 27-year-old Alexis Quinn and an unidentified 22-year-old man, as well as many of the other people wounded by gunfire — who ranged in age from 17 to 69 — are believed to have been innocent bystanders.

It’s unclear whether Garner has an attorney and a listed number in his name couldn’t be found Monday.

District Attorney Larry Krasner said he went to the scene the morning after what he called “a horrific and a senseless act of violence” and found it “chilling — no less chilling that it happened in more than 10 places around the country over the space of a few days.”

The city’s police commissioner, Danielle Outlaw, called it “a dark day” for the city. Mayor Jim Kenney called the shooting “beyond devastating.”

South Street is known for its entertainment venues and night life with multiple bars, restaurants and businesses. Surveillance video from local businesses showed scores of people fleeing as the gunfire broke out. Police are also investigating several other nearby shootings, one fatal, to see whether they might be related, officials said.