PHILADELPHIA, USA (AP) — The first US church official convicted of covering up sex-abuse claims against Roman Catholic priests was sentenced today to three to six years in prison by a judge who said he "enabled monsters in clerical garb ... to destroy the souls of children."

Monsignor William Lynn, the former secretary for clergy at the Archdiocese of Philadelphia, "helped many but also failed many" in his 36-year church career, Common Pleas Judge M Teresa Sarmina said.

Lynn, who handled priest assignments and child sexual assault complaints from 1992 to 2004, was convicted 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 sentence for sexually assaulting an altar boy in church in 1999.

"I did not intend any harm to come to (Avery's victim). The fact is, my best was not good enough to stop that harm," Lynn said. "I am a parish priest. I should have stayed (one)."

Lynn's lawyers had sought probation, arguing that few Pennsylvanians serve long prison terms for child endangerment and their client shouldn't serve more time than abusers like Avery. They plan to appeal the landmark conviction and seek bail while the lengthy appeals process unfolds.

The judge said Lynn enabled "monsters in clerical garb ... to destroy the souls of children, to whom you turned a hard heart."

She believed he initially hoped to address the sex abuse problem and perhaps drafted a 1994 list of accused priests for that reason. But when Cardinal Anthony Bevilacqua instead had the list destroyed, Lynn chose to remain in the job and obey his bishop — by keeping quiet — as children suffered, she said.

"You knew full well what was right, Monsignor Lynn, but you chose wrong," Sarmina said.