(WASHINGTON) -- Police are asking for the public's help after a mass shooting broke out in Washington, D.C., killing a 15-year-old boy.
The Sunday night shooting took place during a festival called "Moechella," which was celebrating Juneteenth, officials said. At about 8:48 p.m., as police were telling organizers to shut the event down, gunshots rang out, D.C.'s Metropolitan Police Department said.
The 15-year-old boy, identified by police as Chase Poole, was killed, police said.
Three others, including a D.C. police officer, were shot and have non-life-threatening injuries, police said.
No suspects are in custody, authorities said.
Police are collecting evidence and interviewing witnesses, Metropolitan Police Chief Robert Contee said in a statement Monday.
A reward up to $25,000 has been offered for information leading to the gunman’s arrest and conviction.
"The person who took Chase's life and brought this violence to our community must be held accountable," Contee said.
Anyone with information is urged to call the Metropolitan Police Department at 202-727-9099.