They decapitate, torture, and extort. Then they pray, and donate to charity.
The "Familia" cartel is perhaps the most extreme example of the paradoxical enemy which Mexico faces as it tries to defeat organised crime.
It is a fight which would be much easier if the cartels were simply maverick gangs on the fringe of society.
But they are, in many areas, part of society.
"La Familia was originally a social structure. And in many ways it still is," says a former Mexico deputy attorney general and organised crime expert, Prof Samuel Gonzalez Ruiz.
The group is believed to have originated in the 1980s as a loose self-protecting coalition between marijuana and opium farmers in the state of Michoacan.
By the 1990s the farmers, who had formed an alliance with the neighbouring Gulf cartel, were running a profitable smuggling business.
Like other Mexican drug cartels, they were benefitting from the massive, successful, clampdown on drug trafficking led by the US authorities across the Caribbean. The strategy pushed the flow of drugs west, into Mexican territory.