LOS ANGELES (AP) — An eight-year investigation into how the Roman Catholic Archdiocese of Los Angeles handled clergy abuse cases suggests "the possibility of criminal culpability" by members of the archdiocese leadership, but investigators don't have enough evidence to file charges, a lead prosecutor wrote in a memo provided Wednesday.

The investigation of alleged sex abuse by priests remains active, but a criminal conspiracy case against archdiocese officials was "more and more remote" because of the passage of time, Deputy District Attorney William Hodgman said in the May 26 memo.

Investigators have insufficient evidence to fill in a timeline stretching over 20 years and are hampered by the statute of limitations, wrote Hodgman, who did not name any church leaders by name in the sections of the three-page memo that were not redacted.

The district attorney's office subpoenaed documents from the archdiocese and hoped to use the material to build more cases, but the effort was stymied by reluctant victims and insufficient evidence to corroborate what was in the documents, the memo said.

The memo was released in response to questions about District Attorney Steve Cooley's handling of the priest abuse investigation, which began in 2002. Cooley is in the final week of a campaign to become the Republican nominee for California attorney general.

Cardinal Roger Mahony has come under fire for his handling of several abusive priests during his tenure in the Los Angeles archdiocese and agreed to pay $660 million in 2007 to more than 500 alleged clergy abuse victims.

A federal grand jury is also probing the archdiocese's handling of the scandal and has subpoenaed a former Los Angeles priest convicted of child molestation and a monsignor who served as vicar for clergy under Mahony.

Mahony's attorney Michael Hennigan has said the cardinal was not a target of the investigation. Hennigan did not immediately return a call Wednesday seeking comment.

Hodgman's memo only refers to the church hierarchy. It does not name Mahony as a subject of its investigation.

Archdiocese spokesman Tod Tamberg said he had not seen the memo. Still, any suggestion of criminal wrongdoing by Mahony or others in the church leadership was false, he said.

"Our documents and actions have been scrutinized for nearly 10 years by judges and investigators, and numerous archdiocesan officials have spent hundreds of hours answering questions under oath," he said.

"While Cardinal Mahony has said that mistakes were made in dealing with individual cases of abuse in past decades, no facts have established that these mistakes were anything other than mistakes," Tamberg said.

Prosecutors have won convictions against six priests since 2002 and were forced to dismiss 11 cases in 2003 after the U.S. Supreme Court found a law that extended the statute of limitations in some sex abuse cases was unconstitutional.

Investigators are currently pursuing a case against another priest, the memo said.

Clergy abuse victims reacted angrily to Hodgman's findings and accused Cooley of not doing enough to crack down on the archdiocese and Mahony.

"We know church officials and church lawyers are extremely shrewd. Still, it's boggling that Cooley can't find a single member of the hundreds of the Los Angeles archdiocesan staff who can be charged," Barbara Dorris, outreach director of the Survivors Network of Those Abused by Priests. said in a prepared statement.

Mahony, 74, will retire next year. His replacement, Archbishop Jose Gomez, was welcomed to the archdiocese in a special Mass last week and will serve alongside Mahony until his retirement.