The first Catholic priest in the United States to be charged with covering up his subordinates' sexual abuse of children arrived in court Monday, March 26 for a landmark trial in Philadelphia, AFP reported.

Prosecutors are targeting Monsignor William Lynn for allegedly shuffling two priests suspected of child abuse to other positions around the Philadelphia, thereby enabling the crimes to continue.

The role of such a senior official, whose co-defendant Reverend James Brennan is accused of sexually abusing boys in the 1990's, makes the trial the first of its kind in the United States.

In a surprise pretrial twist Thursday, the other co-defendant, defrocked priest Edward Avery, pleaded guilty to his own sex crimes, thereby avoiding trial. He was immediately sentenced to between two-and-a-half and five years in prison.

It was not immediately clear how Lynn's lawyers would deal with this setback, since they have said they planned to challenge the credibility of the sex abuse allegations.

The accusations against the three men read like many other church sex abuse scandals. But with the trial attracting heavy media attention, the sordid details of the allegations will be in burning focus.

With a high-up official in the dock for allegedly shielding perpetrators of sex abuse, the case threatens to widen the legal onslaught over a scandal that has already bled the Catholic Church of credibility and money.