A former Franciscan friar from King of Prussia can't withdraw the guilty plea he entered in 2003 after confessing to killing a popular Cleveland pastor, an Ohio judge ruled.

Cuyahoga County Common Pleas Judge Joan Synenberg issued the ruling today, nearly 18 months after a lawyer for Daniel Montgomery claimed that prosecutors withheld evidence in the case and ignored signs that Montgomery may have falsely confessed to murder.

Montgomery's case was the subject of a four-part series in The Inquirer in July 2011. The articles cited evidence and police records Montgomery said were never shared before he accepted the murder and arson plea deal that spared him the death penalty but carried a prison term of 24-years to life.

Synenberg, who will step down from her seat this week after losing a reelection bid last month, did not write an opinion in the case. Her order, which was publicly docketed on Monday, said the claim was barred by res judicata, a legal doctrine which limits litigants from retrying issues that have already been judged.

Montgomery's lawyer, Barry Wilford of Columbus, said he would consider an appeal. A spokeswoman for the Cuyahoga County Prosecutor's Office said prosecutors had no comment on the ruling.

Montgomery's parents, who live in King of Prussia, were disappointed but not surprised. Wilford had advised the family there was "a slim chance" of persuading the judge to reopen the case, Janice Montgomery said.

"Of course, Dan was hopeful," she said.

Montgomery, 47, has been jailed since his arrest in December 2002, a day after firefighters found the body of the Rev. William Gulas, in the scorched remains of the St. Stanislaus rectory.

A former peace activist and honor student, Montgomery had joined the Franciscans, a Catholic religious order, in the mid-1990s. After years of training and religious study in the Midwest, he arrived at the Cleveland parish in the 2002, but struggled to fit in.

Days before the blaze, his Franciscan superiors told Montgomery they were transferring him. They also were quietly making plans to dismiss him from the order.

On the day Gulas died, Montgomery said he was sleeping in his upstairs bedroom when a ringing phone woke him. He smelled smoke, called 911 and fled, saying he didn't know Gulas was in his first-floor office.

A day later, the coroner determined Gulas died not from the fire, but a bullet to his chest. Montgomery became the chief suspect.

After a police interrogation that lasted nearly eight hours, Montgomery confessed to the killing. His two-page confession, typed by a detective and signed by Montgomery, said he "wanted to hurt someone" after learning he was being transferred.

The confession said Montgomery bought a loaded .38 caliber gun for $40 at a nearby convenience store, shot Gulas, tossed the weapon in his office and set the fire.

Montgomery has since denied the killing, saying that he was mentally unbalanced at the time of his confession. His trial lawyer, he said, ignored his repeated claims of innocence and pressed him into a plea deal.

Police records obtained by The Inquirer showed that detectives had discredited parts of the confession. The owner of the convenience store where Montgomery, allegedly bought the gun told police neither he nor his employees had sold the friar a gun and said he had surveillance tapes to prove it.

Dozens of investigators scoured the grounds and neighborhood but couldn't find the murder weapon that Montgomery allegedly dropped at the scene. An officer reported that Montgomery kept suggesting places to look but conceded his mind was "a blank to the details."

Records also showed that a month after the killing, detectives found the dead pastor's cellphone on a fugitive wanted on drug and gun charges. Police never determined how he got Gulas' phone. Nor did they pursue clues that $1,500 was missing from a safe in the pastor's office.

In a bid to withdraw the plea, Wilford claimed police hid or ignored evidence, including that Gulas may have been killed by a robber. He called the confession "a model of unreliability" after a "marathon" interrogation.

Prosecutors Sal Awadallah and Mary McGrath argued that Montgomery entered "knowing, voluntary, and intelligent guilty pleas" and his motion didn't come close to proving the manifest injustice needed to reopen a case.

They cited an affidavit from Henry Hilow, the lawyer who negotiated Montgomery's plea deal, in which he claims he informed the defendant before the plea about the about the missing money and the discovery of the priest's cellphone.

Montgomery, who is serving in a medium-security prison in Marion, Ohio, is not eligible for parole until 2026. His mother said he has faith he will one day be exonerated.

"His innocence just isn't in question," Janice Montgomery said. "He is innocent."

Contact John P. Martin at 215-341-2597, at jmartin@phillynews.com, or @JPMartinInky on Twitter.