Completing a prolific downfall that started with allegations of rape, former Montgomery County Republican Party Chairman Robert J. Kerns agreed Monday to a plea deal that requires him to spend 15 years as a registered sex offender and two years on probation.

Kerns pleaded no contest to misdemeanor indecent assault of a female worker from his law firm after an alcohol-fueled office party in October 2013.

Kerns, 67, will spend no time in jail.

For a man who once shared the spotlight at gatherings with Gov. Corbett, the deal was a relatively soft landing. At the time of his arrest a year ago, he faced allegations that he raped the woman, then 51, and drugged her with the sleeping aid Ambien.

But the case faced hurdles almost from the start and shook the Montgomery County District Attorney's Office along the way.

The accusation that the woman was drugged turned out to be false, the result of a hospital lab report misread by investigators, and forced local prosecutors to relinquish the case.

After the state Attorney General's Office took over, a district judge threw out some of the most serious charges against Kerns - rape of an unconscious victim and sexual assault - because of a lack of evidence.

After the hearing in Norristown on Monday, Deputy Attorney General Daniel Dye conceded to reporters that some of the charges that remained, including felony aggravated indecent assault, would be difficult to prove in court.

But Dye equated Kerns' no contest plea to an admission of "You got me," as opposed to the more forthright "I did it," if he had pleaded guilty. In the end, Dye said, the victim supported the plea deal and has begun to move toward closure.

In a statement, the woman said: "I will not say this has been an easy road. But I do believe it is one that promotes healing and brings power back to you."

Kerns declined to comment after the hearing. His attorney, Brian McMonagle, said Kerns chose not to fight the misdemeanor charge to spare the victim's family and his own the ordeal of a contentious trial.

Dye said he does not expect the victim to file a civil lawsuit, saying that her coming forward "isn't about money."

The Inquirer does not identify victims of alleged sexual assaults.

The woman told investigators that Kerns drove her home after both were drinking with coworkers last October at a Blue Bell restaurant, then sexually assaulted her.

Kerns, who is married, left his Lansdale-based law firm and stepped down as GOP chair when the allegations went public last fall in a grand jury indictment.

The case, now closed, could continue to affect the prosecutor's office, however.

Responding to the error over the misread lab report, District Attorney Risa Vetri Ferman last month created two new positions within her office to try to prevent such mistakes from happening again. She said she would hire or appoint a deputy district attorney for professional standards to lead independent case reviews for other members of the office. A second new position, assistant chief of trials, will oversee the investigations and prosecutors in that division. That post has already been filled by Assistant District Attorney Jesse King, she said.

Ferman also enlisted the Quattrone Center for the Fair Administration of Justice at the University of Pennsylvania Law School to analyze what went wrong in her office's handling of the case. The center's findings are yet to be released.