(CNN) Within the Nxivm community , group founder Keith Raniere was viewed as a humanitarian and a mentor.

"But you saw him for what he was -- a con man, a predator, a crime boss," prosecutor Moira Penza told jurors Monday.

Closing arguments in Raniere's racketeering trial have begun and prosecutors drilled home their claims that the "Nxivm" self-help group he founded was secretly a sex cult set up like a pyramid scheme.

Prosecutors have shown the 16-person Brooklyn jury evidence of a number of crimes, ranging from images of child pornography to testimony from a woman who said she was tied to a table by Raniere and then forced to have oral sex performed on her by someone else.

"The defendant can't hide anymore. A light has been shone in the darkness and his crimes have been exposed. Trust the evidence, trust your judgment," Penza said.

Raniere has pleaded not guilty to charges including racketeering, sex trafficking, sexual exploitation of a child and human trafficking. He did not testify in the case and his defense attorney did not call any witnesses, but his attorney has argued that his relationships with Nxivm followers were consensual.

He has been in federal custody in Brooklyn since he was arrested in Mexico last year.

Over six weeks , several women testified about how they blindly obeyed their "masters," screamed when they were branded with Raniere's initials near their bikini lines and were pressured to have sex with him.

Raniere ran an Albany, New York-based company that offered pricey "self-help" classes to thousands of people across the United States, Canada and Mexico for two decades. An actress who testified in court said he was revered by his students, and some saw him as one of the smartest men in the world.

'A crime boss'

Prosecutor Moira Penza walked jurors through the seven counts they would have to consider for Raniere -- most of them stemming from the secret group within Nxivm called "DOS."

Multiple women testified they were misled about joining the group and were told it was a "women's empowerment" group. They later found out they would become "slaves" who would be expected to have sex with Raniere, send him nude photos and have his initials branded onto their bodies.

"The defendant relied on his female sex partners to approach, groom and recruit more partners," Penza said.

Penza described the way women who became "slaves" and "masters" within DOS as "turning victims into victimizers."

"The defendant tapped into a never-ending flow of women and money," Penza said. "(He was) a crime boss with no limits and no checks on his power."

However, defense attorney Marc Agnifilo previously told CNN he felt that Raniere firmly believes his ideas are sound, humanitarian ideas.

"He thinks DOS is a good idea and is a pro-woman group. He created it to have women have their own society ... where men would play no role," Agnifilo said.

In his closing arguments, Agnifilo cautioned jurors to consider whether any actual crimes have been committed. He argued there was no sex trafficking in DOS because there was no commercial aspect to the sexual activities alleged by the victims.

"Nxivm is a business that's really about making money," Agnifilo said. "There's nothing businesslike whatsoever about DOS."

The crimes Raniere directed and participated in span nearly 15 years, Penza said. She walked jurors through the seven crimes he has been charged with: racketeering, racketeering conspiracy, wire fraud conspiracy, forced labor, sex trafficking conspiracy, sex trafficking and attempted sex trafficking.

The racketeering charge itself has more than a dozen underlying acts as part of the charge, and jurors have to find two of them to be proven in order to return a guilty verdict for racketeering.

Prosecutors say dozens were lured into secret sex society

The women in DOS, like most Nxivm members, were originally drawn into the group because they wanted to learn how to be more successful . A former Nxivm member who was not part of DOS, Mark Vicente, said in court that people would pay for courses costing $7,500 for 16 days. One of those sessions, he said, cleared his feelings of claustrophobia while stuck in traffic jams.

"I had never seen anything that was that effective," he said. "I was blown away."

The women Raniere recruited for his "inner circle" saw him as their master and they eventually came to view themselves as "masters" as they recruited more women to be their "slaves," a criminal complaint said.

Marc Agnifilo, Raniere's attorney, previously told CNN that Raniere created DOS as a way for women to have "their own society ... where men would play no role." But prosecutors say Raniere sat at the top of the pyramid group.

Lauren Salzman , 42, who pleaded guilty in federal court to charges of racketeering and racketeering conspiracy in March, testified she was a master and had six slaves of her own. She was told that the group would teach women to be "master of your own life."

While recruiting them, the masters would insist the recruits provide information about themselves as "collateral" to encourage the recruits to keep information about DOS a secret, according to an affidavit prepared by an FBI agent and filed with Raniere's arrest warrant.

Several women testified in court that they shared sexually explicit photos, granted access to their bank accounts and recorded videos with damaging stories that would hurt their families and those closest to them. Some of the women said the statements were not even truthful.

After being accepted into DOS, members would be branded near their bikini line with Raniere's initials, prosecutors and victims said.

During the trial, prosecutors presented a series of recordings of conversations between "Smallville" actress Allison Mack and Raniere in which they discuss a ceremony for the branding. Mack pleaded guilty to racketeering and conspiracy charges before the start of the trial.

"Do you think the person who's being branded should be completely nude and sort of held to the table like a, sort of almost like a sacrifice," Raniere said in the recording.

Salzman took the stand and spoke about having a ceremony for her six slaves. The first to be branded writhed in pain, she said.

"She was squealing and screaming, and it looked horrendous," Salzman said. "It scared the other girls."

Salzman also said she and other masters would paddle their "slaves" with leather belts. Raniere would call in to check how it was going, she testified.