The gunman who shot dead two New York City police officers had a history of violence and mental illness, according to a top police official.
Ismayyil Brinsley, 28, shot and killed officers Wenjian Liu and Rafael Ramos as they sat in their patrol car Saturday in Brooklyn. Brinsley then fled into a nearby subway station where he shot and killed himself.
Prior to the shooting, Brinsley posted anti-police and anti-government messages on Instagram and alluded to taking revenge for the deaths of Michael Brown and Eric Garner, both unarmed black men who died at the hands of white police officers.
Brinsley was black. The officers he killed were Asian and Hispanic.
New York City Mayor Bill de Blasio described the murders as an attack on all police. The mayor has called for a halt to protests until the funerals are held for the two policemen.
Police said Brinsley had a history of mental illness and had attempted to commit suicide several times, including last year when he tried to hang himself.
According to his family, Brinsley had a troubled childhood and was often violent, New York City Chief of Detectives Robert Boyce said Monday.
Brinsley's mother said though he was from a Muslim family, he was not radicalized in any way.
Long rap sheet
Boyce said Brinsley had been arrested nearly 20 times for crimes ranging from petty theft to making threats. He said Brinsley was estranged from much of his family and that his mother expressed fear of him and said she had not seen him in a month.
Hours before the shootings in New York, Brinsley shot and wounded a former girlfriend in Baltimore in the eastern state of Maryland.
Baltimore police warned that Brinsley had threatened New York police on the woman's Instagram account. But Commissioner William Bratton said his officers received the alert too late to prevent the attack.
The shooting comes at a time of increased tension in New York and around the United States, following the decisions by grand juries not to indict white police officers in several confrontations that resulted in the deaths of unarmed black men.
Police departments in cities around the country have been put on high alert out of fear of copycat killings.
In an interview with NBC's Today Show, Bratton confirmed that tensions between the police force and de Blasio remain high, adding that the mayor has lost the trust of some officers.
Extra $400 million
But Bratton said he does not blame the mayor, adding that the police department has received from the city an extra $400 million to improve police training, improve facilities and acquire new technology.
De Blasio has been criticized by officers over his campaign against the departments stop-and-frisk tactics, a practice in which people, mainly those from poor and minority neighborhoods, were stopped for exhibiting what officers deemed "suspicious behavior."
De Blasio and the president of the Patrolmen's Benevolent Associate, Patrick Lynch, have been locked in a public battle over treatment of officers following the grand jury's decision there not to indict the officer in the Garner case.
Just days ago, Lynch suggested police officers sign a petition that demanded the mayor not attend their funerals should they die on the job. On Saturday, some officers turned their backs on de Blasio when he walked into the hospital where the two slain officers were taken.