LOS ANGELES (CBSLA) — George Tyndall, a former longtime University of Southern California gynecologist accused of sexually assaulting 21 women, pleaded not guilty Friday to six newly filed felony charges.

Former USC gynecologist George Tyndall, wearing a face shield, enters a not guilty plea to six newly filed felony charges in Los Angeles Superior Court on July 24. (CBSLA)

READ MORE: 'Supercharge' Storm Set To Bring Heavy Rainfall To Southland

Prosecutors filed the latest charges — five counts of sexual penetration of an unconscious person and one county of sexual battery by fraud — earlier this month.

RELATED: DOE Investigation Finds USC Failed To Appropriately Respond To Allegations Against Gynecologist George Tyndall

The new charges involved alleged crimes against five women while the 73-year-old was working at USC’s health center between 2011 and 2015, according to the Los Angeles County District Attorney’s Office.

READ MORE: Residents Around Alisal Fire Burn Area In Santa Barbara County Ordered To Evacuate As Storm Arrives

Tyndall was initially charged in June 2019 with 18 felony counts of sexual penetration and 11 felony counts of sexual battery by fraud involving 16 other women dating back to 2009. He pleaded not guilty to those charges and was released on bail.

RELATED: USC Reaches $215M Settlement Over School Gynecologist Accused Of Sexual Misconduct

A preliminary hearing date is scheduled to be set Sept. 25. The hearing will determine whether there is enough evidence to allow the case against Tyndall to proceed to trial.

If convicted as charged, Tyndall could face up to 64 years in a state prison, according to the D.A.’s office.

MORE NEWS: Report: Baldwin Was Practicing Holstering His Prop Gun When He Shot, Killed Halyna Hutchins

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. City News Service contributed to this report.)