The five women described Mr. Roma as a charming and charismatic teacher who cultivated a streetwise persona and emphasized perseverance, sacrifice and dedication to craft. The women, as well as some former students who posted anonymously online about Mr. Roma’s teaching, said that he could be an unsparing critic, but also had the ability to instill confidence and inspire.

One of the women, Ash Thayer, a filmmaker and artist in Los Angeles, said she studied with Mr. Roma in the mid-1990s at S.V.A., then in the graduate program at Columbia, where she was also his teaching assistant. In 1999, Ms. Thayer said, she was working in Mr. Roma’s office at Columbia shortly after a mutual friend, the photographer Raghubir Singh, had died. Ms. Thayer said that she was sitting at a desk when Mr. Roma asked her to turn around. His penis was erect, she said, and he moved toward her. She repeatedly said “no,” but Mr. Roma placed his penis in her mouth before she pushed him away and left, Ms. Thayer said, estimating that the encounter lasted perhaps 30 seconds.

“I froze,” she said. “He committed oral rape against me.”

Allison Ward, a student at S.V.A. in the mid-1990s, said she had several sexual encounters with Mr. Roma. One occurred in a classroom, she said, recalling that she “was mortified and embarrassed but went along with it.” Ms. Ward said that she had wanted to please Mr. Roma and gain his acceptance, adding “he was the first person in my life who had connected my passion for photography with a path forward.” Mr. Roma did not force any contact, she said, but had been “predatory” and had “crossed a line” by seeking a sexual relationship.