NEW YORK (AP) — A New York City doctor was charged Monday in connection with the alleged sexual abuse of at least six women, including several patients who were drugged, filmed and assaulted during appointments at a prestigious local hospital, prosecutors said.

Zhi Alan Cheng was arraigned Monday on charges of sexually abusing three of his patients at New York-Presbyterian Queens hospital and raping three other women inside his apartment in Queens, New York. He pleaded not guilty to the charges.

The 33-year-old gastroenterologist was terminated from his hospital job in December after his arrest for allegedly raping a female acquaintance in his Queens home. At the time, the woman told authorities she had discovered videos of Cheng abusing her and multiple other women.

As investigators searched his home and devices, they uncovered a trove of video evidence showing the doctor abusing women inside his home and workplace, according to the new indictment.

The footage showed Cheng groping three hospital patients, including a 19-year-old and a “seriously ill” 47-year-old, prosecutors said. All of the women appeared to be unconscious during the abuse, suggesting Cheng used anesthesia to sedate them, according to court documents.

Multiple types of liquid anesthesia were recovered from his home, alongside recreational narcotics such as cocaine and ecstasy, the court documents say.

An attorney for Cheng did not immediately return a request for comment.

In a statement, Queens District Attorney Melinda Katz said the evidence pointed to “a serial rapist, someone willing to not only violate his sacred professional oath and patients’ trust, but every standard of human decency.”

The arrest follows the sentencing of another doctor in the NewYork-Presbyterian Hospital system, Robert Hadden, a gynecologist who allegedly abused 245 women over the span of two decades. He was sentenced to 20 years in prison in June.

Cheng’s alleged abuse took place over a much shorter period of time, between 2021 and 2022. But prosecutors said they had additional evidence to suggest that Cheng assaulted other women at different locations in New York City, Las Vegas, San Francisco and Thailand, although he has not been charged in connection with those incidents.

Angela Karafazi, a spokesperson for New York-Presbyterian, said Cheng’s alleged conduct was “a fundamental betrayal of our mission and our patients’ trust.”

The hospital intends to review its patient safety policies and implement additional training for all employees, she said.