His office has also become more aggressive in prosecuting other sex crimes. In 2012, the year that Mr. Hadden was arrested, the Manhattan district attorney’s office prosecuted 59 percent of the sex crimes it had investigated, according to data from the office. That figure increased to 93 percent in 2018.

‘I trusted him’

The investigation of Mr. Hadden, a gynecologist with Columbia University and NewYork-Presbyterian Hospital, began in June 2012 when a patient told the police that during an exam, he had licked her vagina and touched her nipples.

Many of the accusers had been his patients for years. Some said in interviews that at first Mr. Hadden seemed unassuming, with a gentle demeanor and a comforting bedside manner.

He kept photos of his son and daughter on his desk.

“There was nothing about him that was alarming,” said one of the six women Mr. Hadden was charged with abusing, who was pregnant when she was his patient in 2012. She asked that her name not be disclosed.

The woman, identified in the indictment as Victim No. 6, said the abuse started with Mr. Hadden asking questions like, “How do you orgasm?” He asked about her husband’s penis size and made unsolicited suggestions about sexual positions she might find pleasurable.

During one visit, he forcefully pulled her pants and underwear down and grabbed and cupped her buttocks, hips and vagina, according to court records.

On her last visit, he conducted an internal exam by inserting his fingers into her vagina without gloves, according to the woman and court records. A nurse was not in the exam room. The woman never returned and for a time kept what had happened to herself.