He accused his followers of damaging his property and poisoning him, according to evidence from the government. Witnesses testified that he extracted false confessions from them during hourslong interrogations, then used those admissions as leverage to demand hundreds of thousands of dollars in compensation for imagined infractions.

Mr. Ray threatened to dismember one student while standing over him holding a knife, prosecutors said, and threatened to shatter another’s skull with a hammer. He was also accused of forcing a young woman into prostitution. Years later, she said, he tightened a plastic bag over her head while she fought for breath. About six months after that, she fled New York and Mr. Ray.

“He used the threatening displays of violence both to create fear and maintain control over his victims,” a prosecutor, Mollie Bracewell, said during her closing statement to the jury. “His victims would be too terrified to say no to his demands.”

Defense lawyers argued that Mr. Ray had become caught up in a group delusion created by his daughter’s friends and roommates, some of whom suffered from mental illness. Those young people, the defense said, embellished some of Mr. Ray’s tales of intrigue about Mr. Kerik and other topics, creating a “fantastic conspiracy” targeting Mr. Ray and leading him to collect confessions as evidence.

“The world that Larry and the others cultivated over the course of a decade may not be one that you or I could ever understand,” one of Mr. Ray’s lawyers, Marne Lenox, told jurors during her summation. “But for Larry and the others involved, through the looking glass this world was real.”

While making their case, prosecutors drew upon journal entries, email messages and written confessions by students. At one point they introduced into evidence a list of academic articles found on Mr. Ray’s hard drives, including one titled “Cult Membership: What Factors Contribute to Joining or Leaving?” and another called “Mind Control: The Ultimate Terror.”

Prosecutors also introduced photographs and audio and video recordings that provided a glimpse of life with Mr. Ray. One video shows a group of young people decorating a tree in Mr. Ray’s Manhattan apartment while listening to the song “It’s Beginning to Look a Lot Like Christmas.” Another shows a student, Claudia Drury, calmly telling Mr. Ray she had poisoned him with mercury, cyanide and arsenic — something she testified she had not actually done.