(CNN) More than 20 MS-13 gangsters and associates have been indicted on federal charges of racketeering and murder for allegedly taking part in a violent Southern California crime spree that an indictment unsealed this week says included the slaying of one victim who was dismembered and had his heart cut out.

"One of the Justice Department's highest priorities is to dismantle and attack MS-13," Nick Hanna, the US Attorney for the Central District of California, said Tuesday in announcing the charges.

The 78-page grand jury indictment paints a chilling picture of the criminal activity of Mara Salvatrucha, or MS-13, in the Los Angeles area, where the gang has had a presence since forming there in the 1980s.

The indictment targets at least 21 people who are accused of violent acts in the name of the gang that includes murder of rivals and anyone cooperating with or perceived as cooperating with law enforcement. The indictment says they trafficked drugs across state lines, protected other clique members from law enforcement, and collected extortionate rent from local business owners.

Another defendant is charged as an accessory after the fact.

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