A white police officer in suburban St. Louis fatally shot a 18-year-old black man who pointed a gun at him outside a gas station on Tuesday night, the authorities said.
The episode occurred less than five miles from Ferguson, Mo., where the shooting death of an unarmed black teenager in August by a white officer prompted months of protests over the use of force by the police.
St. Louis County Police identified the shooting victim as Antonio Martin, 18, of St. Louis. The officer was not identified.
In a statement, the police said that a police officer from Berkeley, Mo., was doing “a routine business check” at a Mobil gas station near the St. Louis airport around 11:15 p.m. on Tuesday when he approached two men he saw along the building’s side.
“The Berkeley police officer exited his vehicle and approached the subjects when one of the men pulled a handgun and pointed it at the officer,” the county police department, which is leading the investigation, said in a statement. “Fearing for his life, the Berkeley officer fired several shots, striking the subject, fatally wounding him. The second subject fled the scene.”
The police said they had recovered a handgun at the scene.
Police released surveillance tape that showed the police car pulling into the gas station parking lot. The officer appeared to get out of the car, turn on his flashlight and speak for several seconds with two people.
The video was taken from a distance but the episode did not appear to turn confrontational until one of the men turned away, reached down and then turned back to face the officer, appearing to point his arm straight out. The police said the man was holding a 9 mm handgun. At that point, the video stops; the shooting itself is not shown.
In a news conference Wednesday, Chief Jon Belmar of the St. Louis County Police extended his sympathy to Mr. Martin’s family and said such events “are nothing but tragedies.”
But Chief Belmar, who was criticized for how his department responded to unrest in Ferguson, said the surveillance video appeared to show that the officer was in immediate danger and that using a Taser or pepper spray was not a realistic option at that moment.
“You have somebody that’s pointing a gun at a police officer,” Chief Belmar said. “There’s not a lot of time. I can imagine that most of us would feel that we’re in imminent danger of losing our lives.”
Chief Belmar said that the officer had gone to the gas station to respond to a call about a theft. He said the officer, who was 34, had been on the Berkeley force for about six years. The officer will be placed on administrative leave pending an investigation.
Investigators believe that the officer fired three times, striking the suspect once. They do not believe that the suspect fired his gun.
The mayor of Berkeley, Theodore Hoskins, said the city would conduct a separate investigation. “You couldn’t even compare this with Ferguson or the Garner case in New York,” he said, referring to the fatal shooting of Michael Brown in Ferguson and the death of Eric Garner in New York.
Mr. Hoskins, who is black, said that a majority of Berkeley’s police force was African-American. “Our police officers are more sensitive, and it’s because of the black and white relationship that they interact,” he said. “That’s why I believe we’re different than the city of Ferguson.”
Chief Belmar said the officer had a body camera but was not wearing it at the time of the shooting. The police cruiser was equipped with a dashboard camera, the chief said, but it was not clear whether that was recording. The video will be examined by investigators, he said.
Mayor Hoskins said he was “not concerned” that the officer was not wearing the body camera. He said the department recently acquired a limited number of the devices and training is still underway.
“It would have been helpful,” the mayor said, “and in the future, when we get well-trained, there will be a severe penalty for any officer that does not turn it on.”
After the shooting, a large crowd gathered at the station. Chief Belmar said there were three instances of explosives, likely fireworks, being set off, and bricks or rocks that were thrown at police. At least two officers were injured, and four people were arrested on charges of assaulting an officer. By sunrise, the crowd had dissipated.
Since Darren Wilson, the white officer in Ferguson, fatally shot Mr. Brown, 18, protests have been almost daily occurrences around St. Louis. The demonstrations, which later spread across the country, have focused on the use of force by police officers against black men and highlighted a lack of trust between many around St. Louis and the police.
Missouri officials on Wednesday also released an estimate of costs — $12.5 million — for the Missouri National Guard and the Missouri State Highway Patrol, which were called in to handle the protests in Ferguson since Mr. Brown’s death in August.
Berkeley, a mostly black suburb with about 9,000 residents, is among the dozens of small, working-class municipalities that surround St. Louis.
The suburb borders Ferguson, where an intensified round of protests began last month after a grand jury decided not to indict Officer Wilson. Though the demonstrations there have been mostly peaceful, two nights of sometimes-violent actions left several businesses and police cars burned and looted in the St. Louis area.
Since the grand jury decision in the Ferguson case, at least three other similar cases have occurred across the country.
A grand jury’s decision in New York not to indict a white officer in the death of Mr. Garner, who was black, has spurred almost daily protests. In Milwaukee on Monday, the county prosecutor said he would not charge Christopher Manney, a white police officer who shot and killed a black resident, Dontre D. Hamilton, in April after a struggle in a park. And on Tuesday, a grand jury in Houston declined to indict a police officer, Juventino Castro, in the fatal shooting of Jordan Baker, an unarmed black man, at a strip mall in January.