Fr Lawrence Murphy died in 1998 with no official blemish on his record
Sunday mass at Milwaukee's Catholic Cathedral is quieter than it used to be.
For weeks, the American media has been dominated by claims that Church leaders covered up child abuse and failed to punish paedophile priests.
As a result, Fr Carl Last's congregation is getting smaller.
"People are getting fed up with the Church and deciding not to attend," he says. "If they do come to mass - many are holding back their financial contributions."
Milwaukee is at the centre of allegations that are affecting the Roman Catholic Church worldwide.
For more than 20 years, Church leaders here failed to take decisive action following warnings that Fr Lawrence Murphy was sexually abusing boys while running the St John's School for the deaf.
The Archbishop of Milwaukee has admitted that his predecessors made mistakes in handling the case. Fr Murphy was removed from his teaching role in 1974, but never prosecuted or stripped of his priesthood.
But now one of Fr Murphy's victims is seeking to pin the blame higher up the Church hierarchy. The unnamed man has filed a lawsuit against the Pope.
Attorney Jeff Anderson: ''This is the first case we have brought directly and exclusively against the Vatican''
His lawyer Jeff Anderson says he wants to prove the Vatican was negligent and force it to release any files it has on abuse cases involving priests.
Mr Anderson told BBC Radio 4's The Report: "We want the Vatican to come forth with all documents containing evidence of crimes against children.
"Until then, there is a grave and serious problem and all trails and responsibility leads directly to one place - the Vatican, to the Pontiff and his predecessors."
But is there any hard evidence that Pope Benedict XVI covered up or failed to act in the Fr Murphy case?
The Vatican has described the lawsuit as "without merit".
It says that the first it knew of allegations about Fr Murphy was in 1996, when the then Archbishop of Milwaukee, Rembert Weakland, forwarded the case to the Church's watchdog, the Congregation for the Doctrine of the Faith (CDF).
Archbishop Weakland feels the Vatican's response was disappointing
The man in charge of the CDF was the current Pope - then known as Cardinal Josef Ratzinger. He has been accused of failing to respond to two letters from Archbishop Weakland asking for help to defrock Fr Murphy.
So was the Pope dragging his heels in order to protect the priest?
Fr Timothy Radcliffe had regular dealings with the CDF when he was Master of the Dominican order in the 1990s. He sees a more banal explanation for the delay.
"The CDF is a very small organisation. In 1996, it employed around 40 fairly young and inexperienced priests and most of their time was taken up dealing with matters of doctrine.
"For disciplinary matters, you would typically have one priest responsible for the whole of the United States, so I think it's entirely possible that these letters simply fell between the cracks."
But the Pope has also been accused of intervening to prevent Fr Murphy from being stripped of his priesthood.
In 1998, Fr Murphy wrote directly to Cardinal Ratzinger asking him for mercy.
Four months later, his deputy, now Cardinal Tarcisio Bertone, wrote to Archbishop Weakland suggesting that he seek a "pastoral solution" involving tighter restrictions on Murphy, instead of defrocking him.
This letter mentions Fr Murphy's appeal to Cardinal Ratzinger and has been interpreted as evidence that the man who is now Pope ordered clemency for a serial sex abuser.
But did Cardinal Ratzinger see Fr Murphy's letter and did he push for his Church trial to be stopped?
A former CDF insider has told the BBC that, on matters of doctrine, Cardinal Ratzinger would see every letter addressed to him. Cases could then be delegated to junior clerics, but would always cross Cardinal Ratzinger's desk again before a final decision was made.
But Fr Timothy Radcliffe does not think this was the case for disciplinary matters in the 1990s.
"Ratzinger is a theologian and he concerned himself with doctrinal issues," he said. "That was his expertise and what interested him.
"I think he delegated everything he possibly could because his own desire was to get on with teaching and studying and writing. I doubt this would have crossed his desk."
Archbishop Weakland says that he was disappointed when, after a meeting with Cardinal Bertone in Rome, he received a memo from the CDF reiterating the suggestion that he tighten restrictions on Fr Murphy rather than proceeding with the Church trial.
"I would have liked to continue with the case and have it judged and be sure Fr Murphy was stripped of the priesthood," Archbishop Weakland told the BBC.
"I got he feeling that the CDF's canon lawyers were not attuned to the pastoral implications, the hurt of the victims."
Victim Steven Geier is angry that Fr Murphy escaped punishment
Shortly after receiving the memo from Rome, Archbishop Weakland halted Fr Murphy's Church trial.
Two days later, Fr Murphy died.
But the Church lawyer who helped Archbishop Weakland prepare the case against Fr Murphy says that he was not under orders to halt the trial.
"I've seen sharper letters from Rome," said Fr Thomas Brundage, who was also the presiding judge in the Murphy case. "It did seem to leave open the door to us saying no because it was not a direct order."
Fr Brundage added that, far from being obstructive, the CDF had lifted the time limit for abuse allegations to allow the case against Murphy to go ahead.
"They could have stopped it in its tracks at very beginning," he said. "But they didn't.
"People get the sense from the secular press that Cardinal Ratzinger was directly responsible for this case, but you've got to show proof. Speaking as a judge, I have not seen proof in either direction."
The BBC has learned that Papal representatives in America were informed of allegations about Fr Murphy twice in the 1970s - long before Cardinal Ratzinger was at the CDF.
Although the CDF did not have formal responsibility for child abuse cases until 2001, the Murphy case should have been referred to the Congregation because it involved solicitation in the confessional - one of the most serious offences under church law.
Vatican spokesman Fr Federico Lombardi refused to answer specific questions about the Murphy case, but said that allegations that the Pope failed to act were unfair.
He told the BBC: "The Pope is in reality the leader of the line of transparency and clear-decision making to solve this problem and not to have any more any aspect of covering up such problems."
Vatican lawyer Jeffrey Lena described the lawsuit as "an attempt to use tragic events as a platform for a broader attack" on the Church.
Since 2001, the process for dealing with abuse by priests has been streamlined and all cases are referred to a team of 10 priests at the CDF.
But back in Milwaukee, there is anger that Fr Murphy went unpunished even though the church received reports of his abuse as early as the 1950s.
Steven Geier, a former student at a school for the deaf, was 14 when Murphy molested him. Nearly 50 years on, speaking through an interpreter, his anger is still raw.
"I started complaining when I was 15. I told three different priests and the police. All those years, but no-one listened to me.
"Fr Murphy should have been in jail. He was very lucky because he was out until he died. It didn't do me any good at all."
The Reportwill be broadcast on BBC Radio 4, on Monday 26 April at 2030 BST. You can listen again via the BBC iPlayeror download the podcast.
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