Pope John Paul II has accepted the
resignation of a Roman Catholic bishop in the United States who was arrested on hit-and-run charges.
O'Brien was taken ill after being arrested
Thomas O'Brien - the spiritual leader of more than 400,000 Catholics in Arizona - was charged with leaving the scene of a fatal car accident.
He also recently struck a deal to avoid being indicted for allegedly sheltering molesters among the clergy in a sex abuse case.
No specific reason was given for his decision to step down.
A two-line statement from the Vatican said the Pope had accepted Thomas
O'Brien's resignation under Church law allowing a cleric to resign for illness or "some other grave reason" that makes him "unsuited for the fulfilment of his office".
The pedestrian in Phoenix, Arizona, on Saturday was struck by the 67-year-old bishop's car and also by another vehicle which has not been traced.
Police arrested the bishop after a partial registration number provided by a witness led detectives to his address.
The bishop told police he had driven away because he thought he had hit a dog or a cat or a stone had been thrown at him.
He was freed from police custody on $45,000 bail.
Earlier this month, Bishop O'Brien relinquished some of his authority in an unprecedented agreement with prosecutors to protect him from criminal charges for shielding priests accused of child abuse.
But the bishop has denied deliberately trying
to cover up cases of sex abuse, which began emerging last year as allegations of years of priestly abuse in the US Catholic Church started mounting.
His car was found to be damaged and the windscreen shattered
The BBC's Justin Webb in Washington says his arrest was greeted with dismay by American Catholics, who had hoped to put the scandals that have dogged their church behind them.
Bishop O'Brien was not being charged with causing the crash because the pedestrian was
jaywalking, a police spokesman said.
"If the bishop had remained at the scene, in
all likelihood he would not have been charged with any crime," he said.
After being arrested, the bishop was briefly taken ill and transferred to hospital.