By JIM SALTER
Associated Press

ST. LOUIS (AP) — An off-duty St. Louis police officer shot and killed a black 18-year-old who had fired at him, authorities said Thursday. The killing led to an angry demonstration, with some protesters likening it to the August killing of an unarmed black 18-year-old by a white officer in nearby Ferguson.

St. Louis Police Chief Col. Sam Dotson said the 32-year-old officer, whom he didn’t identify, was patrolling the historic Shaw neighborhood in his police uniform for a private security company at around 7:30 p.m. Wednesday when he saw three males, and one of them ran off before stopping.

When the officer did a U-turn, all three ran, so the officer gave chase, first in his car and then by foot. During the chase, he got into a physical altercation with the one he eventually killed, Dotson said at an early-morning news conference.

Dotson said that at one point, the suspect’s shirt raised and the officer saw what he thought was a gun. “The officer said he wanted to be certain it was a gun and did not fire at that point,” he said.

The chief said the suspect, whom he didn’t identify, ran up a hill, turned and opened fired on the officer, who returned fire and killed the man. Ballistic evidence shows that the teen fired three shots and tried to fire again but his gun jammed, he said, noting that the 9mm gun was recovered.

The officer, a six-year veteran of the St. Louis police force whose race wasn’t immediately known, fired off 17 rounds. Dotson said he didn’t know how many of those bullets struck the suspect, or why the officer, who wasn’t hurt, fired that many shots.

“An investigation will decide if the officer’s behavior was appropriate,” he said.

People who described themselves as relatives of the man who was killed told The St. Louis Post Dispatch that he was not armed.

Hours after the shooting, a crowd gathered at the scene near the Missouri Botanical Garden. Some shouted “Hands up, don’t shoot” in reference to the fatal shooting in August of an unarmed 18-year-old, Michael Brown, by a white police officer in nearby Ferguson. That shooting led to weeks of sometimes violent unrest in the St. Louis suburb. The officer, Darren Wilson, has not been charged in the shooting.

Dotson said some in the crowd Wednesday night shouted obscenities at officers and damaged police cars, but that the officers “showed great restraint.”

He added: “Any police officer use of force certainly will draw attention.”

No demonstrators were arrested and by 1 a.m. Thursday the crowd had largely dispersed.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Join our Newsletter for the latest news right to your inbox