Mexican Mafia practiced their rituals. "Brujeria" (witchcraft) altars with figurines of the bandit saint "Jesus Malverde" or "Santisima Muerte"

The Mexican Mafia actually forbade its members from "picking up the Bible" or espousing any form of Christianity. Some members of the Aryan Brotherhood were followers of pagan witchcraft, or worshipers of the devil. In taking on these new belief systems many gang members eschewed the moral codes they had previously ascribed to as part of their religious/superstitious upbringing.
In the 1980s, Cuban "Marielitos" brought Afro-Cuban cult beliefs into the Los Angeles drug and gang culture. Santeria, Voodoo, and Palo Mayombe followers became some of the most violent criminal gang members Los Angeles had ever seen. Across the city, small altars with caldrons or "gangas" of fruit, rum, and cocaine, as well as animal blood sacrifices, dotted the map. "Botanicas" (occult pharmacies) that sold the paraphernalia required for these rituals sprang up in every community.
Drug cartels from Mexico practiced their own rituals. "Brujeria" (witchcraft) altars with figurines of the bandit saint "Jesus Malverde" or "Santisima Muerte" (holy death) were common in cartel drug houses. Cartel members wore amulets and placed figurines of occult symbols in their cars. Some openly worshipped Satan.
During the heavy metal music era of the early- to mid-1980s, a new type of gang began to get the attention of gang cops in Los Angeles. Unlike the common "Cholo" gangs, these new gangs were made up of "Stoners," kids who wore black concert T-shirts, leather jackets adorned with spikes and studs, and long hair. They rejected the classic "oldies but goodies" in favor of AC/DC, Led Zeppelin, Black Sabbath, Ozzy Osborne, and Motley Crew.They also rejected the Cholo gang morals and code of conduct. The Hole Stoners, ELA Stoners, MS Stoners (later to evolve into MS-13), and others played by their own rules. Soon these new Stoner gangs outnumbered traditional gang members in East Los Angeles booking cages. In turn, they were ostracized by most Cholo gang members.