During an investigation into the Rollin' 30s Harlem Crips in South L.A., authorities found photos on social media sites associated with the gang showing children flashing the thumbs up and posing with guns.
In one, a young girl in Disney pajamas holds what appears to be an AK-style rifle.
"It's a culture of violence," LAPD Cmdr. Bill Scott said. "When you grow up in a culture like that, violence becomes secondary. It becomes second nature. And that's the cycle we're trying to disrupt."
About three dozen members of the Rollin' 30s Harlem Crips were taken into custody Thursday on federal and state charges after early-morning raids by hundreds of LAPD officers and FBI agents across South Los Angeles.
The arrests on gang, drug and conspiracy charges are the culmination of Operation Thumbs Down, an investigation initiated in 2012 to target high-level shot-callers in the Rollin' 30s Harlem Crips, one of city's 10 most notorious gangs with an estimated 700 to 1,000 members, federal officials said.
The investigation's name refers to a Rollin' 30s hand gesture -- two thumbs pointed up, representing the "H" in Harlem.
The multi-generational gang operates primarily within Jefferson and Martin Luther King Jr. boulevards, and Normandie Avenue and Crenshaw Boulevard. That area has been the scene of 29 homicides in five years, according to the Los Angeles Police Department.
In addition, about 1,100 robberies and 1,075 assaults have been reported in the 1.5-square-mile area that comprises the gang's area.
The Rollin' 30s gang is also suspected of committing a series of residential or "knock-knock" burglaries, according to the FBI. Police departments in multiple counties are investigating those crimes.
"Among the Bloods and the Crips gangs, the Rollin' 30s are among the more sophisticated," Asst. U.S. Atty. Christopher Pelham said.
According to federal investigators, the Rollin' 30s has three factions: "The Avenues," "Denker Park" and "39th Street." Each operates in different geographical areas within the overall gang territory and has its own respective leaders.
But authorities said the gang's activity has spread beyond South L.A.
"We've traced them up into Simi Valley, up into Van Nuys, different parts of the city," said FBI Special Agent in Charge Timothy Delaney. "So they're not only preying on their local community, they're starting to spread out and preying on different areas of Los Angeles."
In addition to federal drug and gang conspiracy charges, many additional cases were filed with the Los Angeles County district attorney's office.
The task force also served 34 federal search warrants and seized guns and drugs, officials said. A smoke shop and wireless store were among the locations raided.
The Los Angeles city attorney's office said it was also pursuing actions against gang-controlled locations, while the office of the inspector general for the U.S. Department of Housing and Urban Development is seeking the removal of gang members from housing units.