Florencia 13: Vicious Mexican American gang linked to LAPD officer's murder, authorities say

The robbery and killing of an off-duty Los Angeles police officer this month was allegedly the work of Florencia 13 (F13), a Latino street gang largely controlled by the Mexican Mafia.

LAPD officer Fernando Arroyos, 27, was gunned down in South Los Angeles during an attempted robbery while he was looking at houses with his girlfriend Jan. 10. Arroyos and his assailants exchanged gunfire and he was hit once, federal authorities said. 

Fernando Arroyos

Arroyos collapsed in an alley and died at a hospital.  

RELATED: LAPD raising money for family of slain officer

Luis Alfredo De La Rosa Rios, 29; Ernesto Cisneros, 22; Jesse Contreras, 34; and Rios’ girlfriend, 18-year-old Haylee Marie Grisham, were charged in federal court with violent crime in aid of racketeering, which carries a potential death penalty and minimum sentence of life in federal prison without the possibility of parole.

The three men are members of F13, Grisham is a gang associate, and they carried out the attack to increase and maintain their position within the gang, the Justice Department said.

According to The Los Angeles Times, F13 was formed in South Los Angeles in the 1950s and is largely controlled by the Mexican Mafia prison gang, which is made up of about 140 men, most of them incarcerated. 

"F13 is a large, multi-generational street gang that previously has been the subject of federal prosecutions, including two large racketeering cases," the DOJ said.

RELATED: 'Over what? A $200 chain?': Mom of slain LAPD officer in disbelief after South LA shooting

The Times reported earlier this month that Los Angeles County Sheriff Alex Villanueva asked federal authorities to handle the situation because he didn't believe Los Angeles County District Attorney George Gascon's office would be tough enough.

The LAPD hosted a fundraiser for Arroyos' family Wednesday at the Olympic Division station where the officer was stationed.

"He was a really humble hard worker, always walked around with a smile, and he was just really, really nice to be around," an officer told FOX 11. "We're going to miss him a lot. He's family to us."

Get updates on this story from FoxNews.com.

Get your top stories delivered daily! Sign up for FOX 11’s Fast 5 newsletter. And, get breaking news alerts in the FOX 11 News app. Download for iOS or Android.

Tune in to FOX 11 Los Angeles for the latest Southern California news.

Crime and Public SafetyLAPDSouth Los Angeles