Nancy Salzman was known to her followers as “Prefect.” She was a co-founder of Nxivm, a cultlike group near Albany in which women were branded with the leader’s initials and forced to have sex with him, federal prosecutors say. Ms. Salzman, a former psychiatric nurse, helped Keith Raniere found the group in the 1990s. In addition to being accused of being part of a criminal enterprise, she was specifically charged with identity theft and altering records to influence the outcome of a lawsuit against the organization. Others charged in the case include Ms. Salzman’s daughter, Lauren Salzman; Clare Bronfman, an heiress to the Seagram’s liquor fortune; and an actress, Allison Mack, best known for her role in the television series, “Smallville.” Ms. Salzman’s daughter, Lauren, was reportedly involved in the secret sorority and oversaw branding ceremonies. For her part, Ms. Salzman worked closely for two decades with Mr. Raniere and developed the behavioral programs that formed the basis of Nxivm. Beginning in the late 1990s, an estimated 16,000 people enrolled in courses offered by Nxivm, which said they were designed to bring greater self-fulfillment by eliminating psychological and emotional barriers. Nxivm has since shuttered its operations.