Comedian Bill Cosby has been hit with criminal charges for the alleged sexual assault of a former Temple University employee.

Newly elected Montgomery County District Attorney Kevin Steele announced Wednesday that his office has charged Bill Cosby with aggravated indecent assault, a first-degree felony, for a December 2004 incident allegedly involving former Temple University employee Andrea Constand.

Cosby will be arraigned Wednesday afternoon in Elkins Park, Pa. prosecutors said.

"The evidence shows Mr. Cosby established a relationship with the victim associated with her work at Temple," Steele said. "The victim came to consider Mr. Cosby her mentor and her friend."

The statue of limitations for the incident lasts twelve years, and would have expired Friday — just two days after charges were announced.

Cosby allegedly drugged by Constand before the rape, Steele said.

"There's not a question of pills being provided to her. There's not a question of what went on as to the digital penetration," Steele said.

The incident happened while Constand was spending time with Cosby, Steele said.

"On two other occasions before the incident … Mr. Cosby made two sexual advances at her that were rejected," Steele said. "On the evening in question, Mr. Cosby urged her to take pills that he provided to her and to drink wine, the effect of which rendered her unable to move or to respond to his advances, and he committed aggravated indecent assault upon her."

More than 50 accusers have come forward this year to claim they were sexually abused by Cosby since last October, when comedian Hannbial Buress joked about the alleged scandal during a stand-up show in Philly.

Constand sued Cosby in 2005 after he did not face criminal charges for the alleged assault. Some of the statements Cosby made in a 2005 deposition in that suit, unsealed in July 2015, contributed to the investigation, Steele said.

Specifically, Cosby admitted giving Quaaludes to women during sexual encounters in that deposition, Steele said.

Cosby has repeatedly denied wrongdoing and has never before been criminally charged for any incident. Many of the alleged incidents occurred decades ago, so the statute of limitations for prosecuting them has long run out.

Cosby testified in 2005 that he had obtained the sedative drug Quaaludes, popular in the 1970s, with the intention of giving them to young women in order to have sex with him, according to court documents unsealed in July as part of a separate legal proceeding against him.

Additional reporting by Reuters. Stay with Metro as this story develops