Three rival Los Angeles gangs united in a rare alliance to conspire to control drug trafficking and carried out crimes that included murder and extortion, federal prosecutors said in announcing a racketeering indictment against 22 gang members.

Gangs that trace their roots back as far as the 1950s along a gritty stretch of the Los Angeles River were brought together by a convicted murderer who ordered the truce from his state prison cell near the Oregon border.

Arnold Gonzales, 55, was named as an unindicted co-conspirator in unifying the Frogtown, Toonerville and Rascals gangs to divvy up drug profits and control crime in northeast Los Angeles.

Gonzales, an alleged member of the Mexican Mafia that directs gang crime from prisons by sending coded messages to disciples outside, allegedly took control of the gangs in 2010 after other incarcerated gang leaders were convicted of racketeering and sent to federal prison.

One member of the alleged conspiracy referred to the brokered peace as the "United Nations."

Former U.S. Attorney Thomas O'Brien, who focused on gang crime as a prosecutor, said the unification of the three gangs was a "unique and dangerous turn" of events.

"Historically, the Mexican Mafia exercised control over numerous individual street gangs in Southern California," O'Brien said. "To actually take this a step further and unite rival street gangs as one is troubling. They don't normally work that way."

Jorge Grey was appointed to direct the so-called Arnold Gonzales Organization on the street, according to the 88-page indictment, which was released Thursday. Grey said he was the mouthpiece for Gonzales.

Grey, 38, was not among the 15 defendants arrested Thursday morning. He and two others remained at large. Four other defendants were previously in custody.

No attorney was listed for Grey to contact for comment.

Grey and others conducted drug and gun deals at Homeboy Industries, a well-known organization that finds work for ex-gang members and removes tattoos, authorities said.

Grey was a former client of the organization. CEO Thomas Vozzo said he was saddened to learn that alleged crimes occurred at "the safe haven we have created."

"Each year, more than 9,000 men and women receive services at Homeboy Industries headquarters," Vozzo said. "We operate with a zero-tolerance policy for illegal activity and believe that people should be held accountable for their actions."

Grey allegedly ordered others to carry out drug sales and collect "taxes" from dealers to be used to fuel business and funnel money to Gonzales

A woman charged in the racketeering conspiracy allegedly deposited $133,000 in Gonzales' prison bank account, which is supposed to be used to pay for phone calls, snacks and other good such as socks and deodorant.