A 17-year-old was arrested on Friday and charged with gun crimes as detectives investigate whether he was involved in a shooting on Sunday at a Baltimore block party that killed two people and wounded 28 others, the police said.
In a statement, the Baltimore Police Department described the teenager as a “juvenile person of interest” in the shooting and said he had been charged with possession of a firearm by a minor, assault weapon possession, reckless endangerment and having a handgun in a vehicle.
The teenager, who has not been publicly identified, has not been charged in the shooting at the block party, although the statement said that detectives believe he was “involved” in the deadly gunfire that traumatized many in the city’s southern neighborhood of Brooklyn.
Members of the city’s homicide unit and SWAT team arrested the teenager at 7 a.m. after executing a search warrant at a home, the police said.
The arrest represented the first potential break in the investigation into the shooting in Baltimore that was staggering for the sheer number of victims, even in a city long plagued by gun violence.
Fifteen of the injured victims were between the ages of 13 and 17, the police said. The two people who were killed were also young: Aaliyah Gonzalez, 18, and Kylis Fagbemi, 20, the police said.
Three victims remained in hospitals on Friday, the police said, and were considered to be in fair condition.
Mayor Brandon M. Scott said in a statement on Friday that bringing the perpetrators of the crime to justice was the city’s “No. 1 priority,” and that he was grateful to those “who had a hand in bringing this person of interest in.”
“Today’s arrest is a signal that with the community’s help we can get justice for Aaliyah, Kylis and everyone who has been impacted by this tragedy — and Baltimoreans have my word that we will not rest until we do,” he said.
Michael S. Clinkscale, the teenager’s lawyer, said his client told him that he did not have a weapon at the party. He emphasized that the teenager had not been charged with homicide or attempted homicide.
“He’s a good young man and he’s saying he was afraid like everyone else” at the block party, Mr. Clinkscale said in an interview on Friday. “He was running away from the shooting. He was actually shot in the lower left leg.”
The shooting raised questions about why there were no police officers at the block party around the Brooklyn Homes, the public housing complex that was at the center of the event. Although it does not have a set date, the party has been held every summer for 27 years, and officers were present last year.
Baltimore’s acting police commissioner, Richard Worley, said at a news conference on Monday that the department learned of the party’s existence only “several hours” before the shooting, which took place just after 12:30 a.m. on Sunday. He said that multiple guns had been used.
Commissioner Worley said that, in past years, the department had found advertisements or social media mentions of the party and had sent officers to monitor it. But this year, he said, analysts and one of the department’s top intelligence officers had not found any of the posts. He also noted that no one had applied for a permit for the event, though he acknowledged that had also been the case in previous years.
“We knew it was coming up at some point, but we had no indication that it was happening that day because we had never seen any advertisements for it,” Commissioner Worley said.
Videos from the party showed hundreds of teenagers and young people dancing and singing along to local rappers. As they shouted and waved their hands in the air, many held up phones to record the revelry on a hot summer night.
After midnight, those phones captured scenes of chaos and terror as teenagers ran from gunfire, people fell to the ground and a mother wailed as she met officers at the crime scene where her daughter, Ms. Gonzalez, had been fatally shot.
Nicholas Bogel-Burroughs contributed reporting.