Police departments across the United States were operating on “high alert” after two NYPD Officers Rafael Ramos and Wenjian Liu were murdered on Saturday. Police departments and unions have advised officers to wear bulletproof vests, patrol in threes, and avoid posting inflammatory statements on social media. They are fearful of copy-cat attacks.

Police Departments On High Alert After NYPD Cop Killings

NYPD suspends all auxiliary patrols for the time being

According to CNN, the NYPD has suspended, for the time being, all auxiliary patrols. Unions have told police officers to respond to every radio call with two cars. Officers have also been asked to not make any arrests “unless absolutely necessary.” The murders of officers Ramos and Liu in broad daylight have heightened fears about the safety of police officials across the country.

The 28-year old gunman Ismaaiyl Brinsley had vowed to retaliate the killings of black men at the hands of white police officers. According to Fox News, Brinsley was black, and the two slain NYPD officers were Asian and Hispanic. Investigators are working to find out if Brinsley had participated in protests over the deaths of Eric Garner and Michael Brown.

A directive warned New Jersey and Newark officers to avoid people looking for confrontations. In a separate memo, the NYPD chief urged officers to limit their comments, including on social media, to “expressions of sorrow and condolence.” Boston Police Commissioner William Evans said the department had issued an alert to warn officers about the NYPD slayings.

Brinsley shot his ex-girlfriend in Baltimore

New York City Chief of Detectives Robert Boyce told reporters on Sunday that Brinsley had been arrested 15 times in Georgia and four times in Ohio. Before killing the two cops on Saturday, he talked to two people on the street and said,” Watch what I’m going to do.” He used a silver handgun that was purchased at a pawn shop in Georgia in 1996. Investigators are working to determine how it ended up in Brinsley’s hands.

A few hours before shooting the NYPD officers, Brinsley had shot his ex-girlfriend Shaneka Thompson at her home in Baltimore. Thompson’s neighbor called the 911 after listening to her screams. Thompson is expected to survive, according to authorities. Hours before killing the New York officers, Brinsley wrote on his Instagram account, “I’m putting wings on pigs today. They take 1 of ours, let’s take 2 of theirs.” He used the hashtags Shootthepolice, RIPMikeBrown and RIPEricGardner (sic.