Updated

Pennsylvania's highest court will review the long-debated prosecution of a Roman Catholic church official who was tried, imprisoned and then freed over his handling of priest sex-abuse complaints.

Philadelphia prosecutors want to restore Monsignor William Lynn's 2012 child-endangerment conviction, which an appeals court threw out last year. Lynn is now on house arrest after serving 18 months of his three- to six-year sentence.

Lynn, 63, was the first U.S. church official ever charged with keeping accused priests in ministry. Philadelphia Common Pleas Judge M. Teresa Sarmina said at sentencing that Lynn "enabled monsters in clerical garb ... to destroy the souls of children."

However, defense lawyers have argued from the start that the endangerment law should not apply because Lynn was never legally responsible for any individual child's welfare. The Superior Court agreed, in a decision posted hours after Christmas last year.

"I hope the court is going to use this as a vehicle to resolve this case once and for all," defense lawyer Thomas Bergstrom said Thursday.

Lynn will remain on house arrest at a Philadelphia rectory until the state Supreme Court decides the case. That could take a year, given the court's request Thursday for written briefs and oral arguments.

Assistant District Attorney Hugh J. Burns Jr., who argued the appeal, declined to comment.

His office had argued at trial that Lynn transferred predators from parish to parish as secretary for clergy at the Philadelphia archdiocese from 1992 to 2004. Lynn's conviction stems from the case of one priest, Edward Avery, found to have abused an altar boy in 1998 after such a transfer.

"I did not intend any harm to come to (the boy)," Lynn said at his sentencing. "The fact is, my best was not good enough to stop that harm."

Lynn's supporters believe he was made a scapegoat for the church's sins, including two cardinals who were never charged.

The state Supreme Court will now weigh two issues: whether Lynn can be held responsible for a victim he never met, and whether his actions were part of a larger scheme that put the boy at risk.

Former District Attorney Lynne Abraham concluded in 2005 that no church supervisors could be charged under the existing laws; the law was revised in 2007. Her successor, Seth Williams, revisited the case when Avery's accuser came forward, and charged Avery, Lynn and three others. Avery pleaded guilty and is serving a 2 ½- to five-year term.