Here are the latest updates:
Update 7:52 a.m. EST Dec. 23: Two people were still in critical condition Sunday, Officer Michelle Tannehill, a Chicago police spokeswoman, told the Chicago Tribune. One was a 40-year-old man who was shot in the chest, while the other was a 21-year old man who suffered a gunshot wound to the back.
Update 10:55 a.m. EST Dec. 22: Authorities said they apprehended two persons of interest Sunday in a shooting that left 13 injured in Chicago.
Chief of Patrol Fred Waller said one of the people in custody was apprehended with a revolver. It was not immediately clear whether he was among the at least two people suspected of opening fire earlier in the day.
The other person of interest was hospitalized with a gunshot wound, though Waller said he was being considered “as possibly the initiator or possibly someone who was firing their weapon."
Waller said shots were fired around 12:30 a.m. at the home on South May Street, causing people to flee from the home. Two people opened fire outside the home, although Waller said it was not immediately clear whether the two were the same ones who fired shots inside.
“(It) looked like they were just shooting randomly at people as they were exiting the party,” Waller said.
Authorities said someone from the party also shot at a vehicle driving down the street.
The shootings appeared to have stemmed from a dispute that began inside the party. Waller called the shooting an “isolated incident” that did not appear to be connected to gang violence.
“It may be a personal dispute,” Waller said. “We don’t know, exactly, because it started inside.”
Victims injured in the shooting ranged in age from 16 to 48.
Authorities continue to investigate.
Update 7:40 a.m. EST Dec. 22: Chicago Police Department spokesman Fred Waller said during a news conference Sunday morning that four of the 13 shooting victims were in critical condition. The other victims were in stable condition, Waller said.
The victims’ ages ranged in ages from 16 years old to 48, Waller said.
The party celebrated the birthday of Lonell Irvin, a 22-year-old man who was fatally shot in April during an attempted carjacking, the Chicago Tribune reported.
"I was awoken by the sound of, seemed like four, five, or six gunshots and it seemed pretty loud, so it seemed kind of close," neighbor Terrence Daniely, 57, told WLS. "I didn't see any commotion when I looked out the window but then shortly after I heard the sounds of people screaming and running from a party on the street."
According to police, 13 people were taken to area hospitals, WLS reported. The ages and conditions of the victims were not immediately available, police told the television station.
The Associated Press contributed to this report.