The former head of the Republican Party in Montgomery County, who resigned from his post earlier this month amid sexual assault accusations, has been charged with rape and assault.

Robert J. Kerns faces 19 charges including counts of rape of an unconscious victim, sexual assault, indecent assault and simple assault, according to court documents filed on Tuesday.

Three of the charges are related to drugs -- possession of a controlled substance, possession with the intent to deliver and rape of a substantially impaired person.

The 66-year-old attorney allegedly assaulted a 51-year-old woman, who worked part-time at his law firm, following an after-work party on Oct. 25 at a restaurant in Blue Bell, Pa., according to court documents.

The woman was unable to drive home from the party, so Kerns offered to drop her off at the King of Prussia Mall, while he attended a political event, court documents state. He said he'd pick her back up afterwards and by then she should be sober enough to drive.

However, prosecutors say that plan was never carried out. According to court documents, Kerns bought a $68 bottle of Chardonnay before leaving the bar. The victim told officials she remembered drinking the wine in the car before passing out.

Kerns allegedly drove the woman to her home, brought her inside and then raped her, the criminal complaint says.

Prosecutors say he drugged the woman with the sleeping pill Ambien and then sexually assaulted her multiple times.

The woman also told investigators she had leg injuries from the attack and that she photographed the wounds. She quit her job the following Monday and reported the alleged assault several days later, officials said.

Montgomery County District Attorney Risa Vetri Ferman said the woman went to the hospital the day after the attack and that "critical forensic evidence" was recovered. Kerns' DNA was also recovered on the woman's clothing, officials said.

"I don't think there's going to be any testimony in this case whatsoever that my client raped anybody or that he ever gave anybody any drugs," said Brian McMonicle, Kerns' attorney.

NBC10 was first to bring the allegations to light on Nov. 13 -- a day after the case went to a grand jury. That day, our crews witnessed several Montgomery County investigators visiting Kerns' Upper Gwynedd law office. Sources also said investigators visited the man's home.

Kerns formally resigned from his post as the head of the Montgomery County Republican Committee, one of the region's largest political organizations, on Nov. 14. He was involved in Montgomery County politics for more than 30 years, according to his former online profile on the party's website.

Kerns was arrested and arraigned on Tuesday. He is being held on $1 million bail, which he is expected to post. However, there are bail conditions.

He's ordered to stay away from the victim, not allowed to enter any establishment that serves alcohol, not consume alcohol and is subject to random alcohol screenings. Kerns will also be required to wear a GPS monitoring device.