[UPDATE BELOW] A police union has sent out an urgent missive to police officers around the city warning that a militant group has targeted them. According to Sergeants Benevolent Association President Ed Mullins, who sent out an email to members yesterday, members of the Black Guerrilla Family are "preparing to shoot on duty police officers...It appears this is an organized action."

According to the News, an undercover cop apparently first reported the rumor on Friday, with identical typed notes appearing at multiple precincts, referring to a threat against an unspecified "Homicide Section." According to SILive, the Black Guerrilla Family was formed in San Quentin Prison in California in the late 1960s; you can read a Washington Post piece about the gang gaining power in Maryland's prison system.

"I still don’t know if it’s real, but I don’t want to take a chance," Mullins admitted to the Post. "I’m warning all of my members, and all police officers are being warned...There is an upheaval of people bitching all over the country against cops." Officers are being strongly encouraged to wear bulletproof vests and carry their "firearm off-duty along with additional magazines."

He continued in his email to officers:

“As you know, the NYPD is going through a very challenging time with no help from Mayor De Blasio. Be assured this organization will do everything in its power and use every resource to protect each of you. If there has ever been a time to work together, it is now. Once again, I am told this information is credible and has been verified. Your priority is to go home at the end of your tour!”

Mullins said he doesn't necessarily believe this is directly related to the Eric Garner grand jury decision: "I think it’s related to the whole atmosphere."

Update: It seems the concerns about an out-of-state militant group targeting the NYPD was perhaps a tad bit hysterical. "The threat information referenced in a recent news story relates to another East Coast City and does not make reference to New York City or its police," the NYPD said in a statement. "While we are aware of the information, it is not deemed to be a credible, specific threat to NYPD personnel. We continue to monitor and investigate any threat information as it surfaces. We will continue to advise all members of the service of any credible information relating to officer safety."

A source told SILive that the threat was actually against the Baltimore Police Department, which actually has a "Homicide Section."

