A 12-month FBI investigation of violent attacks on inmates in the Los Angeles County jail led to arrests and state prosecutors filing charges against 14 people, authorities said on Friday. The assaults were ordered by the prison gang known by the "Mexican Mafia" moniker, according to the FBI.

Non-incarcerated gang facilitators reportedly ordered their jailed associate “sureños” or “soldiers” to either attack or kill several other inmates who were thought to have breached Mexican Mafia rules.

One instance, which law enforcement cited, centered on an inmate who was stabbed several times because the notorious gang thought he was cooperating with authorities, according to Los Angeles County Sheriff’s Department spokeswoman, Nicole Nishida.

He survived the attack, though the gang wanted him dead.

Southern California gang’s prison purpose

The Mexican Mafia provides protection when its members are sent to jail – as long as they abide by the gang’s rules. The Mexican Mafia also holds power over many Southern California street gangs and controls a great deal of extortion, drug activity, and additional crimes, according to Southern California Public Radio (SCPR).

Another inmate, who was targeted, owed money to the gang. The FBI spearheaded a multi-agency task force, out of Pomona Police Department, that monitored phone calls in two additional planned attacks. As a result, the sheriff’s department transferred the intended assault victims to protective custody, according to authorities.

The sheriff’s department runs the jails within Los Angeles County, which houses over 15,000 people every day.

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Some inmates serve their sentences in the county jails to reduce the state’s prison population. The effect has been an increase in serious and violent offenders within the county’s jails. The population has shifted from prisons to jails, Nishida said.

Two of the alleged gang members arrested for the serial attacks were not already in custody: 29-year-old Daniel Bustamante, Long Beach, CA, and 33-year-old Jose De Jesus Rivera, Compton, CA. They were arrested at their homes on Thursday.

FBI-led investigation started last July

July 2016 is when the FBI started investigating the attacks ordered from outside the jail, authorities noted. The gang’s facilitators were reportedly involved in additional crimes, such as possessing and selling stolen vehicles for the Mexican Mafia.

Alleged gang members arrested, and who were already incarcerated, include: Sergio Chavez, age 20; Miguel Arciniega, age 20; Jose Salazar, age 28; Greg Gonzalez, age 30; Willam Membreno, age 30; Rene Arana, age 31; Daniel Ramos, age 31; Miguel Garcia, age 33; Eyreick Arballo, age 33; Edgardo Moreno, age 40; Victor Hernandez, age 40; and, James Piano (whose age is not available).

The defendant's slated arraignment is Wednesday at Los Angeles County Superior Court, Compton branch.

In 2008, the FBI San Gabriel Valley Safe Streets Task Force was established and comprised various agencies and members: Special Services Unit, California Department of Corrections and Rehabilitation (CDCR), Operation Safe Jails, Los Angeles County Sheriff’s Department; FBI, Drug Enforcement Administration, Pomona Police Department. Los Angeles County Taskforce for Regional Auto-theft Prevention (TRAP) assisted, as well, in the investigation.