A gunman "ambushed and murdered" two New York City police officers Saturday as they sat in a marked police car before shooting and killing himself on a subway platform in Brooklyn's Bedford-Stuyvesant neighborhood, the city's police commissioner said.
The motive for the attack on Officers Wenjian Liu and Rafael Ramos was not immediately clear. Quoting a law enforcement source, NBC's New York affiliate reported that the gunman may have been seeking retribution against police after posting a threatening message on a social media account.
Commissioner William Bratton identified the suspect as Ismaaiyl Brinsley, 28, and said he was believed to have shot and seriously wounded a woman earlier in the day in Baltimore, Maryland.
New York Mayor Bill de Blasio and Bratton urged the public to tell police if they saw social media postings from people threatening police officers.
De Blasio called the killing of the two officers "a particularly despicable act." U.S. Attorney General Eric Holder condemned the shootings and called them an "unspeakable act of barbarism."
In Washington, a spokesman for the administration said President Barack Obama "has been briefed on the Brooklyn police shooting. White House officials continue to monitor the situation."
The police deaths in Brooklyn — the first deaths of police officers by gunfire in the city in three years — followed weeks of protests in New York and other parts of the United States after separate cases in which grand juries declined to charge two white police officers involved in the deaths of two unarmed black men.
In a protest that took place Saturday, demonstrators against police violence shut down part of the Mall of America in Minnesota, one of the nation's largest shopping centers, a community group said.
Mike Isaac, who lives in the area where Saturday's shootings took place in Brooklyn, told CNN that it was a largely African-American neighborhood and had been tense since the protests touched off by the case of Eric Garner, who died after a chokehold was placed on him by a New York City police officer. "The mood is pretty freaked out," he said.
The Rev. Al Sharpton, a New York civil rights leader who has supported the families of Garner and Michael Brown, a Missouri teen fatally shot by a police officer, said he was outraged by the officers' killings.
"Any use of the names of Eric Garner and Michael Brown, in connection with any violence or killing of police, is reprehensible and against the pursuit of justice in both cases," he said in a statement.
Some information for this report came from Reuters.