They found horrors to fit all kinds of charges - rape, indecent assault, endangering the welfare of children. For church leaders, they mulled obstruction of justice.

But at every turn, prosecutors who investigated sexual abuse by priests in the Archdiocese of Philadelphia said they were stymied - and frustrated - by limitations in Pennsylvania law.

The three-year investigation yielded a fiercely critical report but no new charges, an outcome that District Attorney Lynne M. Abraham called a "travesty of justice."

"I am a servant of the law, and we do only what the law permits us," she said at a news conference.

"Had the law allowed us to arrest or charge or indict people, we would have done so."

The decision came after months and months of debate among prosecutors about how to proceed. Archdiocesan lawyers fought hard at every juncture of the grand jury inquiry - especially as Cardinal Anthony J. Bevilacqua, then the archbishop of Philadelphia, was called to testify 10 times.

The office was roiled by an internal debate whether to charge archdiocesan officials, including Bevilacqua, who the grand jury said concealed priest abuse. The church said it had always protected children and said there was never a deliberate cover-up.

Former prosecutor William Spade, who left the district attorney's grand jury team last year, said he pressed hard for criminal charges.

"I argued at the time that we should have pushed the legal envelope to bring an indictment against members of the church hierarchy to hold them accountable," Spade said.

"I've now reached the conclusion that such a prosecution would probably have been unsuccessful," Spade said, adding that his former colleagues "gave their heart and souls to the investigation."

Maureen McCartney, who worked as a prosecutor on the investigation, also said she and her colleagues tried hard to find a way around the obstacles in the law.

"It was trying to put a square peg into a round hole," said McCartney, now a Temple University law professor.

One church watchdog said that he was impressed by the thoroughness of the report but that Abraham should have put the charges before a jury and let it decide if they were justified.

"The decision not to indict is very depressing," said Terry McKiernan, codirector of the Web site www.bishop-accountability.org

Abuse investigations elsewhere also ended with scathing reports and no charges, but some prosecutors found ways to get past legal hurdles.

In Cincinnati, the archbishop appeared in court to plead no contest on behalf of his diocese to five counts of failing to report abuse to authorities. Prosecutors also extracted a $3 million victims' fund.

And in New Hampshire, the Diocese of Manchester admitted that prosecutors had enough evidence to likely convict the diocese on a child-endangerment charge.

There, prosecutors also had a statute-of-limitations problem but decided the clock should start running when authorities first learned of abuse - not when it happened.

But legal experts said the obstacles in Pennsylvania were all but insurmountable.

Marci Hamilton, a law professor at the Benjamin N. Cardozo School of Law in New York City, said Pennsylvania laws are the worst in the nation for prosecuting priests who abuse children.

Allegations are often old, and the statutes of limitations mean that priests can't be charged. Pennsylvania also narrowly defines what it means to endanger the welfare of a child, which makes it harder to prosecute church leaders for not taking action, Hamilton said.

"The law just didn't provide any possibility," said Hamilton, who assisted the District Attorney's Office in reviewing whether any clergy could be charged.

Under current state law, a prosecution must be initiated before a victim of childhood sexual abuse turns 30. Abraham said her office would lobby hard for legislation that would remove that limit entirely.

Center City defense attorney L. George Parry, a former federal and state prosecutor, said the Pennsylvania Supreme Court is inflexible when it comes to the statute of limitations.

"Unlike Massachusetts and other jurisdictions, the Supreme Court of Pennsylvania has not allowed for any exceptions," said Parry, who represented one abuse victim before the grand jury.

Prosecutors thought about filing a charge against the archdiocese itself; Pennsylvania law allows corporations to be charged criminally if there is ongoing, institutional misconduct.

But that idea also failed because the Philadelphia Archdiocese is legally an "association," not a corporation, the report said.

State Sen. Lisa Boscola (D., Northampton) said she had introduced legislation that would eliminate the statute of limitation on sexual crimes. But, she said, the measure never made it out of the Judiciary Committee.

Boscola said she planned to reintroduce that bill next week and hoped the grand jury report would provide needed momentum.

"This will help put the full-court pressure on," she said.

Abraham's office did prosecute one priest last year: the Rev. James J. Behan, who pleaded guilty in February to sexually abusing a teenager he had met when he taught at North Catholic High School for Boys in the late 1970s.

The statute of limitations was not a problem because prosecutors persuaded a judge that, by leaving Pennsylvania in 1980, Behan had stopped the clock on the statute of limitations.

Abraham said that unless a new victim comes forward, there will be no other prosecutions.

"The perpetrators of these crimes and the people who protected them will never face the criminal penalties that they deserve," Abraham said.

[Contact staff writer Emilie Lounsberry at 215-854-4828 or elounsberry@phillynews.com]