Monsignor William Lynn, 61, of Philadelphia awaits sentencing on Tuesday.
Lynn, the former secretary for clergy at the city's Roman Catholic archdiocese, handled priest assignments and child sexual-assault complaints from 1992 to 2004.
He faces up to seven years in prison after a jury convicted him last month of felony child endangerment for his oversight of now-defrocked priest Edward Avery. Avery is serving a 2 1/2 to five-year term after pleading guilty before trial to sexually assaulting an altar boy in church.
Lynn's lawyers argue that few Pennsylvanians serve long prison terms for child endangerment and say he should not serve more time than abusers.
"Monsignor Lynn has never harbored any intent to harm a child," lawyers Thomas Bergstrom and Jeffrey Lindy wrote. "He certainly never foresaw that the tragic events leading up to (Avery's victim's) abuse would take place."
In 1992, a doctor told Lynn's office that Avery had abused him years earlier. Lynn met with the doctor and sent Avery for treatment - but the church-run facility diagnosed him with an alcohol problem, not a sexual disorder.
Avery was returned to ministry, and sent to live at the northeast Philadelphia parish where the altar boy was assaulted in 1999.
Prosecutors are expected to seek the maximum sentence.
"That Lynn failed to report known child rapists to law enforcement and continued to support and enable the ministry of predator priests, in the face of constant reminders that hundreds of lives had been ruined by these men, is a clear measure of his character (and) his lack of remorse," Assistant District Attorney Mariana Sorensen wrote in a post-trial memo.
Common Pleas Judge M. Teresa revoked Lynn's bail after the June 22 verdict, sending the dazed cleric straight to prison. He now seeks a sentence of time served combined with house arrest, community service, work release or probation.
"The seven-year maximum sentence that the commonwealth advocates would serve no purpose at all - (it) would merely be cruel and unusual," his lawyers wrote.
Prosecutors spent a decade investigating sex-abuse complaints kept in secret files at the archdiocese and issued two damning grand jury reports. They argue that Lynn and unindicted co-conspirators in the church hierarchy kept children in danger and the public in the dark.
Lynn plans to appeal his landmark conviction and seek bail immediately after he is sentenced Tuesday. His lawyers have long argued that the state's child-endangerment statute - revised in 2007 to include those who supervise abusers - should not apply to Lynn since he left office in 2004.
Prosecutors are expected to file their sentencing memo Friday.
The two sides also disagree over who qualifies as a victim in the case. The defense argues that only Avery's 1999 victim and the man's parents should be allowed to give victim-impact statements. Prosecutors want to call some of the trial witnesses who testified about alleged abuse by other Philadelphia priests supervised by Lynn.
Lynn was acquitted of conspiracy and a second endangerment count involving a co-defendant, the Rev. James Brennan. The jury deadlocked on a 1996 abuse claim against Brennan.
Supporters insist that Lynn is being made a scapegoat for the sins of the church. Lynn testified at trial that the late Cardinal Anthony Bevilacqua had to approve all of his recommendations.
Archbishop Charles Chaput took over the archdiocese of 1.5 million people last fall. Chaput did not attend the trial, but visited Lynn in prison this month.