PHILADELPHIA – A Roman Catholic monsignor who became the first U.S. church official branded a felon for covering up sex abuse claims against priests was sentenced Tuesday 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," 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, who is serving a 2½- to five-year sentence after pleading guilty to sexually assaulting an altar boy in church.