LOS ANGELES — New charges have been filed against a former University of Southern California campus gynecologist accused of sexually assaulting young women who were his patients, Los Angeles County District Attorney Jackie Lacey said Thursday.

The additional charges involve five new alleged victims of Dr. George Tyndall, who has previously pleaded not guilty to criminal charges involving 16 women.

The amended complaint adds five counts of sexual penetration of an unconscious person and one count of sexual battery by fraud that allegedly occurred while Tyndall, 73, worked at a USC health center between 2011 and 2015.

Arraignment was scheduled for July 24.

"Dr. Tyndall takes every allegation seriously," said his attorney, Leonard Levine. "However, he continues to be adamant that he has treated every patient within the standard of care and always for a state medical purpose. He is confident when all the evidence is presented and tested in a court of law that he will be totally exonerated."

Tyndall was initially charged in June 2019 with 18 counts of sexual penetration of an unconscious person and 11 counts of sexual battery by fraud, all felonies.

All 21 victims went to the campus facility for annual exams or for other treatment dating back to 2009, prosecutors said.

Tyndall resigned in 2017 and allegations against him became public in 2018 through a Los Angeles Times investigation.

If convicted as charged, Tyndall now faces a possible maximum sentence of 64 years in state prison.

In February, the U.S. Department of Education said it found systemic failures in USC's treatment of allegations of sexual abuse by Tyndall and ordered the school to overhaul its procedures for preventing sex discrimination and to conduct a formal review of how employees responded. Education Secretary Betsy DeVos called it a "total and complete failure to protect students."

USC's new president, Carol L. Folt, pledged to protect the safety of students, faculty and staff and to restore trust in the university.

A federal judge has approved a $215 million class-action settlement between USC and about 18,000 women who saw Tyndall at the university. Payments would range from $2,500 to $250,000, with specific sums decided by a panel of experts.

Hundreds of women have opted out of the federal court settlement and many are pursuing separate lawsuits in state court.