“When you were around him, you were mesmerized by him,” says survivor and former member Ruby Garnett of cult leader Dwight York

On May 8, 2002, cult leader Dwight “Malachi” York, was arrested as he was walking into a grocery store in Eatonton, Georgia — putting an end, authorities said, to his years of sexually abusing the children of his followers.

Soon afterward, local and federal law enforcement officers busted through the gates of “Tama-Re,” the Egyptian-themed compound of York’s United Nuwaubian Nation of Moors.

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There they discovered dozens of female followers, 50 to 75 children, a stockpile of weapons and evidence of York’s sexual depravity, including a stuffed Pink Panther with a penis attached and photos taken at Florida’s Disney World where York would often take his child victims.

Authorities began investigating molestation claims against York two years earlier, when his estranged son, Jacob, and several of York’s victims came forward with accounts of slavery, starvation and sexual abuse dating back decades.

In 2004, York was convicted of five counts of racketeering and six counts of transporting minors across state lines for sexual purposes. He was sentenced to 135 years in federal prison, where he remains at 73.

His group’s history, the crimes he inflicted on others and their stories of survival will be shared on Monday night’s episode of People Magazine Investigates: Cults, airing on Investigation Discovery and exclusively previewed above.

Here are four things viewers will learn from the show.

• For more on the rise and fall of the United Nuwaubian Nation of Moors, subscribe now to PEOPLE or pick up this week’s issue, on newsstands now.

Image zoom Dwight York’s cult compound, Tama-Re Ric Feld/AP/Rex/Shutterstock

1. York Came to Power in the ’70s Preaching Black Supremacy

York, an ex-con and Harlem street peddler, started his own sect in New York City in the ’70s, where he preached a black supremacist ideology mixed with traditional Islamic doctrine.

In 1972, he moved his growing congregation into various apartments he bought in the Bushwick section of Brooklyn and called his new commune the Ansaru Allah Community.

At his headquarters, his followers strictly adhered to his teachings and beliefs. Children attended his schools, women were mandated to work in the office and his male followers were tasked with recruiting new members.

“When you were around him, you were mesmerized by him,” survivor and former member Ruby Garnett says in Monday’s episode. “He was so charismatic. It was just amazing. I thought York was a Messiah.”

York was also a staunch believer in polygamy and had sex with many of his female followers. A select group of his favorites became his wives.

Image zoom Cult survivor Niki Lopez Micheal Anthony Clark

“He gave me a diamond ring,” says Garnett, who wed York at the age of 19. “I was so happy, I cried. I felt special because I am looking at being in his family as a privilege — an honor of service.”

However, when Garnett learned that York had sodomized an underage female follower, her feelings curdled.

“When he told me this story about violating her, in my mind I am saying, ‘Is he testing me?’ ” she recalls. “I was terrified.”

2. York Claimed He Was Royalty

Over time, York’s need to control every aspect of his followers’ lives grew more sinister and sexually depraved, according to former members as well as law enforcement sources and news accounts.

Niki Lopez — who joined the group at age 11, with her mom — was 13 years old when her sexual grooming process began.

At first, she says, York allowed her and a few of the other kids special access to his house to watch cartoons and eat junk food.

“He would give us little treats. … He gave us T-shirts,” Lopez says on PMI: Cults. “We were like, ‘We have short-sleeved T-shirts that no one else has.’ ”

Soon, however, Lopez says she was taught how to perform oral sex by one of York’s wives, who convinced her that sex with him was a Sudanese tradition to prepare them for marriage. (York claimed at one point to be heir to the throne of Sudan.)

One night, Lopez says, she was asked to stay behind at York’s house, where he held her down and raped her. She was 15.

• For more on the abuses of Dwight “Malachi” York and the United Nuwaubian Nation of Moors, watch Monday’s People Magazine Investigates: Cults at 9 p.m. ET on Investigation Discovery.

Image zoom York’s devotees at Tama-Re, his compound in Putnam County, Georgia W. A. Bridges Jr./Atlanta Journal-Constitution/AP

3. York Moved to Georgia After Police Got Suspicious

As time passed, law enforcement in N.Y.C. started to probe York’s possible involvement in criminal enterprises and if his group was being funded by organized bank robberies and counterfeit checks.

As the scrutiny mounted, York moved his followers to Eatonton, Georgia, in 1993.

It was there that his teachings took a bizarre and unpredictable turn.

At first, York called himself Chief Black Thunderbird Eagle, the leader of a lost Native American tribe that fought against early European colonization. He then claimed to be an extraterrestrial from the planet Rizq. Eventually he morphed into the leader of the United Nuwaubian Nation of Moors, proclaiming a philosophy that revolved around Egyptology and UFOs.

York declared that his armed compound — which featured two 40-foot plywood and stucco pyramids and a Sphinx — was a sovereign nation and refused to follow local, state and federal laws.

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Image zoom York’s young followers Courtesy Niki Lopez

Image zoom Dwight York Putnam County Sheriff's Office

By 1998, whispers of York’s sexual depravity reached local enforcement when they learned about a rash of underage Nuwaubian girls giving birth in area hospitals.

However, the turning point in the case came in 2001, when York’s estranged son as well as other followers — including Niki Lopez — came forward with their tales of abuse.

4. More Than 40 Victims Cooperated with Police

After Niki began cooperating with law enforcement, more than 40 victims spoke out to give investigators additional details of sexual and physical abuse at the hands of York, which lead to the raid on his 476-acre compound.

York was arrested and charged with multiple state and federal crimes, including more than 100 counts of child molestation, six counts of transporting minors across state lines for sexual purposes and five counts of racketeering.

He was convicted in 2004 and sentenced to 135 years in federal prison.

“It was kind of liberating,” says Lopez about testifying against York. “I felt like he can’t tell me anything. He can’t make me do anything. That was the first time of me getting my power back.”