A secretive New York group that federal prosecutors say evolved into a sex cult tried to conceal a “horrible evil” behind a facade of self-improvement, a man who spent 12 years in the organization said Thursday at the group leader’s criminal trial.

The man, filmmaker Mark Vicente, is the second witness to testify against Keith Raniere. Raniere is on trial for crimes including sex trafficking for his role running the secretive upstate New York Nxivm group, where prosecutors said he forced women to have sex with him and in some cases branded his initials on them.

Vicente said he was like many of the group’s members when he joined it 2005, buying into Raniere’s pitch of himself as a genius who could help people turn their lives around. It took him 12 years to leave the group after he learned of the sexual practices and other abuse performed on members, he testified.

“It’s a well-intended veneer that covers a horrible evil,” an emotional Vicente said during the trial’s third day in federal court in Brooklyn.

Raniere, 58, has pleaded not guilty to charges including sex trafficking and child pornography. He faces life in prison if convicted.

Prosecutors say women were blackmailed into having sex with Raniere and branded with his initials as part of a secret society within Nxivm called DOS, an acronym for a Latin phrase that roughly means “master of the obedient female companions.”

Defense lawyer Marc Agnifilo has argued at the trial that members joined voluntarily and were never forced to do anything against their will.

Vicente said Nxivm President Nancy Salzman contacted him around 2005 after seeing a film he made about quantum physics and philosophy, saying she wanted to introduce him to Raniere.

That meeting led Vicente to begin his association with the group. He gave jurors a brief crash course on Nxivm, listing more than a dozen organizations and self-improvement programs under its umbrella that cost thousands of dollars.

A former Nxivm and DOS member who was only identified by her first name Sylvie on Wednesday told jurors she was recruited as a “slave” to another woman in the organization. Her “master” eventually ordered her to engage in sexual activity with Raniere, who also took nude photos of her, she said.

Sylvie said she felt she had to do what she was told, both because of years of psychological manipulation by Raniere and others, and because she had given her master compromising material that could be used to blackmail her.

Other individuals who say they were victims of the group are expected to testify. Five of Raniere’s co-defendants, including Salzman, Seagram liquor heiress Clare Bronfman and former “Smallville” television actress Allison Mack, have pleaded guilty to related crimes.

Nxivm, which started under another name in 1998 and is pronounced “Nexium,” was based in Albany, New York.

(Reporting by Brendan Pierson; editing by Scott Malone, Jeffrey Benkoe and Jonathan Oatis)