A former chairman of the Montgomery County Republican Committee in Pennsylvania who resigned last week after being accused of sexual assault was arrested on Tuesday on 19 counts, including rape and drug charges.Sources told several news outlets last week that Robert Kerns had gotten drunk and assaulted a woman following a GOP dinner in October.On Tuesday, Kerns was taken into police custody and charged with rape of an unconscious victim, rape of a substantially impaired person, sexual assault, aggravated assault without consent, aggravated assault of a person unaware penetration was occurring and 8 other forms of assault.He also faces charges of possession of an instrument of crime with intent, possession of a controlled substance and tampering with evidence.At a Tuesday press conference, Montgomery County District Attorney Risa Ferman said the Grand Jury found that Kerns had "delivered a controlled substance and sexually assaulted a woman multiple locations."According to reporter Carl Hessler , authorities said that Kerns had drugged the woman by putting the insomnia medication Ambien in her drink during a Republican Party dinner. He then allegedly raped her multiple times when she lost consciousness.Ferman added that the Grand Jury described Kerns as "predatory and manipulative" and that there were often other victims in those types of cases. She urged any other women who had been assaulted by Kerns to come forward."I give great credit to the victim in this case, she was extremely courageous in coming forward and sharing what happened to her," Ferman said. "I think she should be commended."Kerns resigned as chairman of Republican Party in Montgomery County last week, but continues to serve as the solicitor for Upper Gwynedd and West Norriton Townships and Trappe Borough, and the Police Chiefs Association of Montgomery County. He was expected to be arraigned Tuesday afternoon.Watch this video from Carl Hessler of Montgomery County Courthouse News, broadcast Nov. 26, 2013.