“I’m very sorry for the trouble I have caused,” Ms. Russell told the judge, her voice breaking. “I compromised my own principles.”
Ms. Russell faces between six months and a year in prison under federal sentencing guidelines. She will be sentenced on July 31. Ms. Bronfman faces between 21 and 27 months in prison and will be sentenced on July 25.
Mr. Raniere has denied all the charges against him. “We are going to trial,” his lawyer, Marc Agnifilo, said on Friday. “We don’t believe Ms. Russell and Ms. Bronfman should have been charged, and we are happy they’re out of the case.”
Court papers have described Nxivm as a rigorously hierarchical organization in which Mr. Raniere, who was known as “Vanguard,” demanded obedience from followers. High-ranking members who answered to Mr. Raniere could be equally demanding of those below them.
In March, a co-founder of the group, Nancy Salzman, known as “Prefect,” pleaded guilty. Ms. Salzman, who founded Nxivm in the 1990s with Mr. Raniere, was charged with identity theft and altering records to influence the outcome of a lawsuit against the organization.
Earlier this month, Ms. Mack, an actress who had appeared on the television show “Smallville,” also pleaded guilty to racketeering and racketeering conspiracy charges.
Prosecutors described Ms. Mack as “a first-line master” in the group’s secret sorority, known as D.O.S., an acronym for a Latin phrase that roughly translates to “Lord/Master of the Obedient Female Companions.”