NORRISTOWN - The passage of time.

In Bill Cosby's case, the once beloved, family-friendly entertainer has become a fallen hero with 60 women accusing him of drugging and sexually assaulting them.

The top prosecutors in the Montgomery County District Attorney's Office have changed.

And a key witness to the former district attorney's promise to not charge Cosby - whose testimony the defense says could have kept this case from moving forward at all -- has died.

Though the aggravated indecent assault charges filed against Cosby fell within the statute of limitations, his defense team argued in Montgomery County Court on Wednesday that too much time has passed for prosecutors to level their charges against him.

And for Cosby - whom they say is now blind and unable to identify witnesses and key pieces of evidence -- to mount a proper defense.

Cosby is accused of sexually assaulting Andrea Constand at his suburban Philadelphia home in 2004. He is set for trial in June, but several days of pre-trial hearings have been set to work out numerous pending motions and arguments.

And one of those arguments on Wednesday was related to the passage of time.

A decade ago, former District Attorney Bruce Castor did not charge Cosby after the incident over a lack of credible evidence, defense attorney Angela Agrusa argued, adding the case was closed in 2005, and with the promise from Castor that he would not prosecute, Cosby testified in a civil lawsuit filed by his accuser.

That promise held for a decade, but all of that changed with a new district attorney.

Cosby became a pawn in an election when current District Attorney Kevin Steele ran against Castor and won on a platform that Castor was not tough enough on sexual predators - specifically pointing out in campaign ads that Castor never charged Cosby, she argued.

"He's saying to everybody, 'I'm going to get this guy, I'm going to get this guy,'" Agrusa told the court. Steele won, and now, "He has promises to deliver."

Cosby was charged in December, and though the charges fall within the statute of limitations, Agrusa says the amount of time that has passed violates Cosby's right to due process and a fair trial, and the case should be dismissed.

A change in prosecutors, under case law, is not a valid reason for such a delay, she argued.

"While the government did noting, it gained a tremendous strategic advantage against Mr. Cosby because of the passage of time and the loss of essential pieces of evidence," she said.

Time has taken other tolls.

The only witness, besides Castor, to the promise barring prosecution against Cosby has died.

That was Cosby's former lawyer, Walter Phillips, who represented him in 2005.

Additionally, Agrusa said the prosecution wants to bring 13 other accusers to testify against Cosby to show a pattern of drugging and molesting women over the course of decades. But it's because of those decades, Agrusa argued, that their memories would be faulty.

The same holds true with Cosby, who is 79 and, due to his blindness, is incapable of seeing witnesses, photos and documents to help in his defense.

"He is not a pawn. He is not a meme," Agrusa said. "He is a human being and his rights have been trampled."

Cosby's testimony under deposition, where he acknowledged some of the sexual encounters, but said they were consensual, was the subject of argument on Tuesday as the defense worked to prevent evidence from that testimony from going to a jury.

It's not clear yet how Judge Steven T. O'Neill will rule on it.

Argument will resume in the afternoon.