The Philadelphia Police Department identified two of the three people who were killed in a downtown shooting on Saturday night as 34-year-old Gregory Jackson and 27-year-old Alexis Quinn.
The identity of a third individual who was killed, a 22-year-old male, was not released by police.
Philadelphia Police Commissioner Danielle Outlaw said officers were patrolling South Street, a popular entertainment district full of bars and restaurants, when shots rang out around 11:30 p.m.
Police immediately began treating gunshot victims and an officer observed a suspect shooting into a crowd, prompting the officer to fire his service weapon "several times in the direction of the unknown male, we believe striking him."
One of the three people killed was involved in a fight that led up to the shooting, while the other two were just bystanders, according to Philadelphia police.
"At this time we believe one of the three deceased was a male involved in a physical altercation with another male that was potentially the genesis of the shooting," Outlaw said. "These individuals eventually began firing at one another, with both being struck, one fatally."
At least five guns were involved and two were recovered at the scene, including one with an extended magazine.
Eleven other people suffered gunshot wounds, including a 23-year-old male who was shot multiple times in the torso and was listed in critical condition on Sunday.
Philadelphia set a record with 562 homicides last year, a 13% increase over 2020, according to the city's office of the controller. Before Saturday's mass shooting, Philadelphia had seen 211 homicides so far this year, a slight 5% decrease over the same time period in 2021.
"Once again, we see lives senselessly lost and those injured in yet another horrendous, brazen and despicable act of gun violence," Mayor Jim Kenney said Sunday morning.
No arrests have been made as of Sunday evening.