A suspect is still at large after a mass shooting broke out in Washington, D.C. over the weekend, killing a 15-year-old boy and injuring 3 others.

Officials say that the Sunday night shooting took place during a festival called “Moechella,” which was celebrating Juneteenth. Metropolitan Police Chief Robert Contee said that the 15-year-old boy – identified by police as Chase Poole – was killed. Three other people, including a D.C. Metropolitan police officer, were injured.  The officer is expected to be OK and the two civilians were listed in stable condition.

Metro Police Chief Contee said in a statement Monday that authorities are collecting evidence and interviewing witnesses, but no suspects are in custody.   A reward up to $25,000 has been offered for information leading to the gunman’s arrest and conviction.

Anyone with information is urged to call the Metropolitan Police Department at 202-727-9099.

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