A man has been charged hours after a mass shooting, which Mayor Lori Lightfoot called an “incredible act of cowardice,” wounded 13 people attending a memorial party in Englewood Sunday, including a 16-year-old boy who had been in critical condition.

On Sunday evening, police announced charges were filed against 37-year-old Marciano White, of Beverly. He has been charged with a felony count of unlawful use of a weapon by a felon but authorities did not specify his role in the incident.

According to Cook County court records, White has two felony drug charges, the first a 2006 narcotics conviction and the other in 2007 for possession of cocaine. He remains in custody and is due in Central Bond Court on Monday.

The incident stemmed from a dispute inside the home, Chief of Patrol Fred Waller said at a press conference Sunday morning. Shots were fired inside, and people scattered outside, he said. The gunfire continued as people ran out, with two people appearing to shoot “randomly” at those exiting the building. At one point the shots were aimed at someone in a vehicle.

“It’s a chaotic scene. Listening to the radio, you can hear people who didn’t even know that they were shot were responding as they went home. So I’m imagining some people had some graze wounds and didn’t realize they were shot,” Waller said.

Two persons of interests — including a 25-year-old man who was seriously wounded in the shooting — were being questioned, police said. Officers responding to a ShotSpotter alert saw White quickly leaving the home, clutching a bag across his body, police said. As officers attempted to approach him, he tried to elude them but was taken into custody and found in possession of a firearm, police said.

The victims included nine men and four women between 16 and 48 years old, police said. Seven people were taken to area hospitals by ambulance, and six others went on their own, according to Waller. One person has since been released from hospital care.

Four people were hospitalized in critical condition, including a 16-year-old boy who was taken to St. Bernard Hospital with gunshot wounds to the chest and lower back, police said. The boy’s condition has since been downgraded to “serious,” and a 27-year-old woman who was previously in critical condition has been stabilized.

Two men, 40 and 21, remain in critical condition at the University of Chicago Medical Center and St. Bernard Hospital, respectively, police said. With the exception of the 16-year-old in serious condition, everyone else was in good condition or had been stabilized Sunday afternoon.

Witnesses told police the memorial party was being held to celebrate the birthday of 22-year-old Lonell Irvin, who was fatally shot during an attempted carjacking in April, Chicago police spokesman Tom Ahern said.

While detectives are trying to pinpoint a motive, the preliminary investigation suggests the shooting was an isolated incident.

“Right now, it doesn’t appear to have been a targeted or retaliation-type incident,” Ahern said. “It appears to be more of a personal dispute inside the party that spilled out into the street.”

At her press conference later Sunday morning at the University of Chicago Medical Center, where six of the victims were taken, Lightfoot described the shooting as a “terrible tragedy and, frankly, an incredible act of cowardice.”

She urged those at the party to come forward with what they knew so the shooters could be caught.

“Someone in that room knows exactly what happened,” Lightfoot said.

Lightfoot said those shot were from the city and from out of state. She also took a moment to address young people directly.

“Solving disputes with a gun is never, never the right answer,” Lightfoot said. She planned on visiting the neighborhood later in the day.

Waller said cameras helped investigators get information about what transpired, and CPD plans to bolster police in the area.

“We’re going to have more police presence in that area today as well as the weekend,” he said. “We know that the weather’s going to be somewhat warmer than it normally is during this time so we’re going to have a lot more police presence in that area and in other jurisdictions.”

Police drove slowly down the 5700 block of South May Street, which was quiet, Sunday morning hours after the shootings.

A pair of black boots with what appeared to be blood caked in the fur lining were on the grass outside of the home where the shooting happened. They were next to what appeared to be a piece of a blood covered pant leg — the wrapper for a trauma wound dressing was nearby. Red crime scene tape hung off the stairs leading up to the home.

Ald. Stephanie Coleman (16th), who said the party was in the top unit of the two-story graystone, received eight phone calls from residents about the shooting and immediately went to the scene.

At least 20 police cars were on the scene by the time she got there, and she could sense the worry among residents.

“I saw fear,” she said. “I saw lots of concerned neighbors getting to the bottom of it. I saw children at 12:30 in the morning. Could you only imagine children out because it was just that much activity going on?”

Coleman described the block as “wonderful,” lauding the businesses, residents and families there. She urged residents to speak up and be involved with the safety of the community.

Neighbors, however, pointed out longstanding problems on the block, including at the home where the shooting took place.

“This block is really dangerous, and it’s been like that a long time, and it seems like no one cares and no one’s trying to do anything about it,” said Stephun Lake, who lives a few doors down from where the shooting took place and was awakened by gunshots early Sunday morning.

Lake said this was the “second or third time” there have been an incident at that house.

Though other holiday weekends this year have seen higher numbers of shooting victims — most notably the Fourth of July, in which 68 people were shot — the magnitude and timing of this incident came as a shock to Coleman, who said she was frustrated and disheartened, especially for the children living in the area.

“I’m very saddened, very disappointed that our children ... this is their welcoming not only into the Christmas holiday but to their Christmas break,” she said.

The 13 people shot Sunday morning in Englewood are among 38 who have been shot throughout Chicago so far this weekend. Five of the weekend’s shootings have been fatal.

The last time so many people were shot in one incident in Chicago was in 2013, when 13 people were wounded in a shooting at Cornell Square Park in Back of the Yards.

Area South detectives are investigating.

Contributing: Kathy Chaney, Rachel Hinton and Jermaine Nolen