BERKLEY, Mo. — A Berkeley police officer fired at least three shots at a suspect who pulled a gun on him, the St. Louis County Police chief said at a morning news conference.

Police Chief Jon Belmar said the officer was doing a business check at a Mobil gas station about 11:15 p.m. Tuesday when the shooting happened.

The officer saw two people on the parking lot in the 6800 block of North Hanley Road and began talking with them.

Belmar said one of the people approached the driver’s side of the vehicle.

One of the individuals “produced a pistol with his arm straight out, pointing it straight at the officer kind of from across the hood,” Belmar said.

At that point, the chief said, the officer got his service revolver “and fired what we think is three shots.”

The officer, who is 34 and white, is a 6-year veteran of the department, Belmar said

Belmar said one round struck the suspect, an 18-year-old black male, and one struck a tire of the police car. Police said they did not immediately know where the third round went.

He also said the 9 mm gun found on the suspect had five rounds in the chamber and one round in the magazine. He also said the gun was “defaced.”

The suspect was pronounced dead at the scene. Belmar declined to release his name at the news conference but said he was known to police for various charges including weapons and stealing. A woman at the scene overnight, Toni Martin, said it was her son, Antonio Martin, 18.

Between 200 and 300 protesters gathered at the scene after the shooting, and conflicts broke out between officers and protesters, Belmar said.