Heavens Gate, Branch Davidians, and Jonestown are 3 of the most well known modern day cults because the fate of all 3 ended in self sacrifice and tragedy. Large and I go into depth on The Big 3 during the Twisted History of Cults: Part 1, but what about a cult that became notorious, not for their size of the tragedy, but the tragedies' disturbing nature?
Adolfo De Jesus Costonzo was a drug trafficker in his mid 20's who convinced his group of followers, at Rancho Santa Elena, human sacrifice would give them supernatural powers that would protect them from getting arrested and make them invincible. What started out with roots in the religion of Sangría, turned into Costonzo's own disturbed, dark sect. The Matamoros Cult.
When a student went missing from spring break, the student's brain was found inside a cauldron with a turtle shell, spinal column, and a horse shoe. An all out search for the killer who ritualistically murdered the spring breaker lead authorities to uncover dozens of horribly mutilated corpses buried on Adolfo De Jesus Contonzo's family farm in Rancho Santa Elena.
Costonzo was given the nickname The Pied Piper Of Death for how many people he'd led to a similar sacrificial death, but he was never caught by authorities. With police hot on his trail, Costonzo had ordered someone shoot shoot him before he was apprehended. Constonzo obviously was never charged, but other members involved in the cult were apprehended and arrested.