After being convicted of child endangerment, released, sent back to prison and freed again, Monsignor William Lynn is now trying to block a retrial on the original charges.

Lynn, 66, has a hearing scheduled Wednesday on whether prosecutors withheld potentially exculpatory evidence in his case, according to court records.

Lynn, who served as secretary of clergy for the Archdiocese of Philadelphia from 1992 to 2004, was convicted in 2012. He was the first Catholic administrator in the U.S. to be convicted of a crime related to child sex abuse.

While Lynn was never charged with molesting a child, he was convicted of child endangerment on the grounds he placed a pedophile priest in proximity to a child.

But Lynn’s lawyers argue that new evidence questions the credibility of alleged victim, identified in court as Billy Doe.

In court papers, Lynn’s lawyer Thomas Bergstrom argues that the defense never knew retired police detective Joseph Walsh, who investigated the case, doubted the credibility of Doe.

They interviewed Walsh in November. According to the Inquirer, Walsh told defense lawyers during the interview that after he told a prosecutor he doubted Doe, they responded, “You’re damaging my case.”

Testimony from Doe was used at trial against Lynn, as well a former Catholic schoolteacher and three priests. All five were charged after the District Attorney’s Office released a 2011 grand jury report on child sex abuse in the archdiocese.

Due to a gag order imposed by the judge, DA Seth Williams and Bergstrom are not allowed to comment on the case.

Lynn was sentenced to three to six years in prison on charges of child endangerment in 2012.

An appeals court freed Lynn after ruling that child endangerment laws shouldn't apply to administrators like him in 2013. But the state Supreme Court disagreed and sent Lynn back to prison in 2015. 

He was freed again in August 2016 after an appeals court ruled that certain evidence was improperly allowed at his first trial and ordered a retrial.

Lynn’s retrial is currently scheduled for May 1.