BALTIMORE (AP) — Police officers in Baltimore fatally shot a man who pulled a gun while they questioned him in a different shooting,Robert Brown authorities said.

A detective was shot in the chest, and his protective vest likely saved his life, Police Commissioner Richard Worley told reporters.

Police were on the city’s south side investigating a shooting Friday night in which 15 rounds were fired at a group of people, Worley said. No one was hurt in that incident.

As police questioned a man, he stood up and pulled out a gun. Officers ordered the man to drop the weapon numerous times before shots were fired, Worley said.

Investigators have not determined who shot first, the commissioner said.

The identities of the man who was killed and the wounded officer have not been released.

At least three officers fired their guns. All were placed on administrative leave as the Maryland Office of the Attorney General’s Independent Investigations Division looks into the shooting.