The majority of cases, which can determine whether a priest is restored to ministry or cast out for good, have been concluded. But some have sat unresolved for more than a decade. And the cost of supporting accused clergy continues to mount.

The archdiocese attributes the delays in part to the inherently slow penal process in the church’s justice system, known as canon law, and the deluge of cases after the church’s sexual abuse coverup was exposed.

But the long waits have delayed a resolution for both priests and victims, prolonging the crisis.

Fifteen Boston priests who were removed from ministry in 2004 or earlier still await the conclusion of their canonical cases, in the meantime earning as much as $40,000 a year, plus health benefits. One — the Rev. Paul F. Manning, who turns 72 this year — has not worked in the ministry since 1996.

In each of those cases, an archdiocesan investigator has made an initial finding that at least one abuse allegation against the priest appears credible, and the priest has been suspended from public ministry pending the outcome of his canonical proceeding.

Nicholas P. Cafardi, a prominent canon lawyer and professor at Duquesne University School of Law in Pittsburgh, said that trials conducted by the Catholic Church should not take more than three or four years.

“There is no reason for a canonical process, even with appeals, to take from 2004 to 2012,” he wrote in an e-mail.

Boston archdiocesan officials acknowledge the delays are excessive.

“We get it,” said Monsignor Robert P. Deeley, vicar general of the archdiocese, who is also a distinguished canon lawyer.

Deeley, one of two Americans whom the Vatican summoned to Rome in 2004 to reduce a logjam of sexual abuse cases there, said he has been concerned about the issue since he returned to Boston last year to help run the archdiocese.

“We understand why there is concern about this on the part of the survivors,” Deeley said, “and we are working to resolve the problem as we can for their benefit, and for the benefit of the church and ... for the benefit of the priests themselves.”

In an interview at the archdiocesan headquarters in Braintree, Deeley said the backlog should be considered in context: The church was flooded with some 1,000 abuse complaints at once after the sexual abuse crisis exploded in Boston in 2002. Just two years later, the archdiocese began a round of church closings that precipitated another glut of canonical cases, as parishioners challenged some of the closing decisions.

The Boston tribunal’s docket is also jammed with more routine issues, such as marriage annulments. Last year, there were 500 marriage-related cases alone.

Canonists — usually priests with specialized training in canon law who participate as lawyers and judges — are relatively scarce, Deeley said; about two dozen are working on the abuse cases in Boston. The vast majority are priests with parish responsibilities in addition to their legal work.

Coordinating their schedules for tribunals can be difficult, particularly when a canonist from outside the diocese is participating. Each case involves six canonists — three judges, an advocate for the defense, a “promoter of justice” who represents the church as a whole, and a notary.

Deeley said Cardinal Sean P. O’Malley, the archbishop of Boston, understands the importance of moving trials forward, and that is why the cardinal agreed to send Deeley to Rome to help the Vatican deal with its backlog.

“He is keenly committed to getting the cases done,” he said.

For victims, the wait can be excruciating. A man who first formally accused the Rev. James J. Foley Jr. of molesting him in 1999 had to wait until 2011 to testify in a tribunal. He is adamant that Foley be permanently removed from ministry.

“For years, it’s been us calling them — ‘What have you heard? Where do we stand? What is going to happen?’ ” he said. “I was sour anyway on the church, but it was brutal.”

The man has heard little from the church since, he said. “We’ve been told to hurry up and wait,” he said.