PITTSBURGH — A Roman Catholic priest removed from public ministry in 2009 after an allegation of past child sex abuse pleaded guilty Thursday to a federal charge of possessing child pornography, and a diocesan official said the clergyman could be removed from the priesthood entirely or be assigned to a life of “prayer and penance” by the Vatican.

The Rev. David Dzermejko, 65, of Braddock faces a likely term of more than three years in federal prison when he is sentenced March 20, according to Assistant U.S. Attorney Carolyn Bloch. The priest and his attorney declined to comment after Thursday’s hearing.

Dzermejko was the longtime pastor of Mary, Mother of the Church parish in Charleroi when he was removed from active ministry. He never was criminally charged in the alleged abuse, which dated to the 1980s and involved another parish. The allegations surfaced in 2009 when a couple accused Dzermejko of molesting their son, who had since died. Another man came forward to accuse the priest after seeing news reports about the couple’s claims.