Bruce L. Castor Jr. has said he thought Bill Cosby was guilty.
He has said he would like a chance to prosecute the comedian himself.
But Castor has also said his declaration that he would not charge Cosby in 2005 - when he had the chance as Montgomery County district attorney - might prevent prosecutors from now pursuing their sexual-assault case against the comedian.
How Castor reconciles these positions is likely to play a central role Tuesday at the first pivotal court hearing since Cosby's arrest last month.
Common Pleas Court Judge Steven T. O'Neill has asked to hear arguments on whether a non-prosecution deal that Cosby's lawyers say Castor struck 10 years ago now means the current charges should be dismissed.
Castor is expected to be a key witness.
The proceeding could determine the future of a case more than a decade in the making - former Temple University basketball manager Andrea Constand first accused Cosby of drugging and abusing her in 2005 - and one drawing an unprecedented media spotlight to Norristown's historic courthouse.
Court officials have issued 91 credentials to dozens of news outlets, established an overflow courtroom for reporters to watch on video, and distributed parking passes for nearly two dozen satellite trucks and broadcast crews.
Neither prosecutors nor defense lawyers have released a witness list or indicated how long the hearing could last. But they have traded barbs in a volley of court filings over the last month.
In the latest, on Thursday, Cosby's lawyers renewed their claims of a non-prosecution deal and cited an email Castor sent last fall to his successor, Risa Vetri Ferman, outlining a 2005 oral agreement among Cosby, his lawyers, and attorneys for Constand.
Brian McMonagle, leading the comedian's current defense team, has characterized the deal as an "express agreement," saying Castor "promised" Cosby would never be prosecuted.
District Attorney Kevin Steele said that claims of a non-prosecution deal are meritless and that there is no evidence of a binding agreement. Ferman, who was Castor's top assistant a decade ago, also says no such deal occurred, as have Constand's lawyers.
Cosby's criminal lawyer at the time, Walter M. Phillips, died last year.
But what Castor will say - should he take the stand Tuesday - might not be so certain.
He has remained largely silent since the charges were filed in December. In a letter sent Friday from his lawyer, Castor declined to comment for this story.
His email to Ferman in September appeared to be the first time Castor outlined the deal he said was understood and accepted by all parties, one that spared Cosby from criminal prosecution in return for his willingness to be questioned by Constand's civil lawyers.
In multiple interviews over the previous year, Castor had stopped short of describing such an agreement. Instead, he portrayed his Feb. 17, 2005, news release on the investigation as his own bid to push Cosby to testify in the civil case.
In that statement, Castor declared there was "insufficient" credible and admissible evidence to win a conviction.
"I made a decision that the case . . . was never going to get any better based on what I knew," he told The Inquirer in October. "And I thought that having Cosby punished by having to go through a civil trial or pay a lot of money to avoid it would stop him from engaging in future conduct and would exact some measure of punishment."
But the prosecutors leading the case now have pointed to another sentence in the statement to argue there was no agreement with Cosby: "District Attorney Castor cautions all parties to this matter that he will reconsider this decision should the need arise."
Castor has since said that he was referring to his decision not to discuss the case, not his decision to decline prosecution. But in an interview in fall, Castor suggested the release had actually left the door open to revisit the allegations.
"I put in there that if any evidence surfaced that was admissible then I would revisit the issue," he told The Inquirer in September. "And that evidently is what the D.A. is doing."
Ferman reopened the case after parts of Cosby's 2006 civil deposition were unsealed last summer. In it, he talked openly about his encounter with Constand, which he describes as consensual, and admits obtaining drugs to give to women with whom he wanted to have sex.
Dozens of women have come forward to accuse Cosby of drugging and assaulting them, although Constand's claims are the only ones that have led to criminal charges.
After learning the investigation had been reopened, Castor said, he contacted Ferman through the email now cited by Cosby's lawyers as proof of a non-prosecution deal.
"I wanted to make sure that she knew what I remembered and matched that with what she remembered," Castor told The Inquirer. "It never occurred to us that we would have to think about this case again."
At the time, Castor was locked in an election battle with Steele, Ferman's first assistant. Weeks later, Steele ran a TV ad attacking Castor for not prosecuting Cosby a decade earlier.
Castor fired back in his own ad, claiming Steele could have arrested Cosby as new information surfaced. And Castor continued to maintain in interviews that, if elected, he would review the case.
"I have said repeatedly and for months that if I ever get the opportunity where I get the power to review the investigation into Cosby, I would do so," he said before the election.
Constand has since sued Castor for defamation, claiming he publicly undermined her credibility and misstated facts about her case. Castor has called the lawsuit an attempt to influence the election - one he lost - and vowed to fight it.
Days before Cosby's arrest in December, Castor said he still thought Cosby's 2006 deposition could not be used in a criminal case - and that his 2005 news release would create problems for a revived prosecution. But, he also said he hoped Steele would arrest Cosby if new incriminating information emerged.
"If they come up with evidence that I didn't know about," Castor said, "I'm going to be cheering for the D.A.'s office."