PHILADELPHIA (CBS) – A fierce legal battle is shaping up in the case against three priests and a Catholic Church Monsignor charged in connection with the alleged sexual abuse of boys. Skilled, tenacious, veteran attorneys on both sides are battling over multiple pre-trial issues, and attacks on the alleged victims have raised concern in the district attorney’s office.

All of the defendants, through their attorneys, have denied the allegations and some of the attorneys have publicly challenged the credibility of the accusers, citing substance abuse and legal problems.

Philadelphia DA Seth Williams isn’t buying that argument.

“To say that somehow because what happened to him when he was ten which caused him to become addicted to drugs that somehow we can’t believe him,” Williams said. “I think what has happened to him in his life since that time is more indicative of what happened to him as a child at the hand of those priests.”

Defense attorney Mike McGovern, who represents Father Charles Engelhardt, says the defendants are presumed innocent.

“I think whenever an individual accuses not just one, but two, but three separate people of abuse from the same school from over ten years ago, his credibility had to be tested at a preliminary hearing.”

And the two sides are arguing over whether there should even be a preliminary hearing or if the case should go straight to trial.

Reported by Tony Hanson, KYW Newsradio