There will be drama in Philadelphia.

A landmark case involving Catholic officials' response to sex abuse is planned for retrial May 1 of next year. The accused is a monsignor who was the first Catholic official convicted for his supervisory actions regarding a priest accused of abusing children.

But claims of new exonerating evidence and a court's decision to throw out the monsignor's previous sentence make the situation more complex.

Monsignor William J. Lynn, 65, was released from Pennsylvania state prison Aug. 2 on $250,000 bail. He had served 33 months in prison on a conviction that was overturned in late 2015.

The monsignor was sentenced to three to six years in prison after a 2012 trial.

Msgr. Lynn himself was not accused of sexually abusing children. However, he was convicted on one felony count of child endangerment for failing to protect children from a priest with a known history of abuse.

The monsignor's defense lawyer Thomas A. Bergstrom said the case against his client was "over the top, inaccurate and dishonest," the Philadelphia Inquirer reports. He said the monsignor had served almost the minimum sentence under the vacated conviction, in addition to 18 months' house arrest.

However, Philadelphia District Attorney Seth Williams said he had no doubts about re-trying the case. He charged that the monsignor "helped create a playbook for handling someone who alleges that an archdiocesan priest is a pedophile." He said he thought there was sufficient evidence for a retrial and he would not bring the case if he was not sure he could secure a conviction.

Msgr. Lynn had served as the Philadelphia archdiocese's Secretary for Clergy from 1992 to 2004. As such, he was responsible for investigating priests accused of abuse.

His first trial included 13 weeks of testimony. Most of the testimony reviewed Archdiocese of Philadelphia records about its investigations into two dozen priests dating to 1940, the Philadelphia Inquirer reports. Prosecutors said the history showed the priest was part of a dominant culture in the archdiocese.

In December 2015 a Superior Court panel, by a vote of 2-1, ordered a new trial for Msgr. Lynn. It agreed with his lawyers that the prosecutors had wrongly tainted the jury's judgement in its use of historical evidence of the Church's handling of sex abuse, the Philadelphia Inquirer reports.

The priest's lawyers said the evidence was prejudicial and inflammatory and drove the jury toward a guilty verdict. Bergstrom has argued that Msgr. Lynn was a scapegoat.

Assistant District Attorney Brian Zarallo said that prosecutors will re-use some of the historical evidence in the re-trial, but this is dependent on agreements in pre-trial hearings.

The case for which the monsignor was convicted involved an accusation from a man who said that two priests and a parochial school teacher sexually abused him when he was a 10-year-old altar boy. The accuser, known in court records under the pseudonym "Billy Doe," alleged abuse that took place in the 1998-1999 school years.

Msgr. Lynn had allowed one of the accused priests, Fr. Edward V. Avery, to live at the rectory of Philadelphia's St. Jerome Catholic Church despite a history of sexually abusing children. Avery, now 73, pled guilty to the charges involving Doe in March 2012 and is still serving his prison sentence. He was laicized in 2006.

The other priest accused of abuse was the late Father Charles Engelhardt, who died in prison in 2014 at the age of 67. He was still appealing his prison sentence of six to 12 years.

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The other man accused was parochial school teacher Bernard Shero, now 53, who is serving a sentence of eight to 16 years.

In January 2013, Avery was a witness at Englehardt's and Shero's trial. But he recanted his plea and said he pled guilty only to avoid a longer prison term. He denied knowing his accuser, Englehardt, and Shero.

The alleged victim who accused the three men is now 28. At the trial defense attorneys strongly questioned his history of drug use, lies, crimes, and discrepancies between his trial testimony and his initial statements to police and church investigators.

The accuser rejected claims he had made false accusations and said his drug and emotional problems were due to the abuse he suffered.

Both prosecutors and defense attorneys will have to decide how to use the new revelations and claims.

Bergstrom said he has since acquired previously unavailable reports from investigators and forensic psychiatrists that cast doubt on the credibility of the accuser's allegations.