The teenager is being held in juvenile detention, Seattle Mayor Katie B. Wilson said in a press conference

A 15-year-old who opened fire on the crowd at the Bite of Seattle festival is now in police custody, Mayor Katie B. Wilson said in a press conference on Monday, July 27.

“The Seattle Police Department detained a 15-year-old juvenile in connection with the shooting,” said Wilson, 44. “The teen was booked into the Judge Patricia H. Clark Children and Family Justice Center for investigation for firearms violations and first-degree assault.”

Wilson said authorities currently believe the teenager “opened fire in the crowd, but details are still under investigation.”

His first court appearance was on Monday afternoon, though no formal charges have been filed yet, Wilson said.

“We believe that two people exchanged gunfire outside the Seattle Center Armory,” Wilson continued.

“A 19-year-old man, a 44 year old man, and a 56-year-old woman were killed. Two died at the scene, and a third passed away at Harborview Medical Center,” Wilson said in the press conference.

The King County Medical Examiner’s Office has identified the victims as Junior Cee Niko Semo, 19, Carlos Israel Sanchez Villalba, 44, and Ashley Whitehead, 56.

The 19-year-old was arrested in connection with the shooting as well, but died from gunshot wounds after exchanging fire, NBC News reported.

“I want to acknowledge that this has been an especially tough week here in Seattle,” Wilson said. “Thursday night, there was a shooting near or near Aurora in North Seattle. Again, in Capitol Hill on Friday night, and now at the Seattle Center last night.”

“While the police department continues their investigations, we cannot let up on implementing a multi-prong gun violence strategy,” Wilson added. “We know that gun violence can be prevented.”

In a previous press conference shared by FOX 13 Seattle, Seattle Police Assistant Chief Tyrone Davis said gunshots were heard at 6:01 p.m. local time at the annual Bite of Seattle event on Sunday, July 26, and once officers arrived at the scene, they found a total of seven victims with gunshot wounds.

PEOPLE has reached out to the Seattle Police Department.

Source: https://people.com/15-year-old-in-custody-after-shooting-at-a-seattle-food-festival-leaves-3-dead-mayor-says-12028085