The state Superior Court has handed down what may be the final written opinion in one of the most closely-followed murder trials in Pennsylvania history.

More than two decades have passed since Lisa Michelle Lambert was first convicted for the 1991 murder of Lancaster teen Laurie Show, whom Lambert stalked and murdered because Lambert thought Show, then a 16-year-old high school sophomore, was romantically involved with Lambert’s boyfriend, Lawrence Yunkin. Yunkin, whom Show had accused of raping her, and another woman, Tabitha F. Buck, were also convicted in Show’s throat slashing.

In deciding Lambert’s second Post-Conviction Relief Act petition, a three-judge panel ruled Monday that Lambert had failed to meet the “newly-discovered evidence” exception to the PCRA’s timeliness requirement. Instead of new evidence, Lambert had introduced a “newly willing source” to her decades-long allegations that her 1992 bench trial rendered her the victim of prosecutorial misconduct.

At least one tribunal has bought into Lambert’s story. That came in 1997, when U.S. District Judge Stewart Dalzell of the Eastern District of Pennsylvania declared Lambert “actually innocent,” writing that police and prosecutors had stained Lambert’s trial by destroying or tampering with evidence that Lambert insisted would have proved her innocence.

Among Lambert’s claims was the allegation that police framed her to cover up an alleged gang-rape in which three East Lampeter Township police officers sexually assaulted Lambert just months before the murder took place.

But the U.S. Court of Appeals for the Third Circuit twice upheld Lambert’s conviction and sharply criticized Dalzell’s handling of Lambert’s case. The Third Circuit said Dalzell failed to show appropriate deference to the findings of Pennsylvania state courts. Effectively, the appeals court ruled, Dalzell let Lambert retry her case.

At that time, the case drew comparisons to the popular television shows Perry Mason and Matlock. More currently, the details seem fitting for an episode of Law and Order SVU or Criminal Minds.

The case history of Commonwealth v. Lambert includes a bench-trial conviction, a failed direct appeal in state courts, perhaps the most watched federal habeas petition in recent memory, a 300-plus-page opinion from the trial judge on Lambert’s PCRA try, another habeas petition in which Dalzell recused at the request of prosecutors, and the Third Circuit’s subsequent dismissal of Lambert’s second federal petition.

In her most recent legal saga, according to the opinion Monday, Lambert has alleged that she has a letter written by the now-deceased prosecutor who handled her trial in 1992 that bolsters her claims. According to Lambert, the opinion said, former Lancaster County prosecutor John A. Kenneff wrote to his former client, Warren Raffensberger, admitting that the events leading up to Raffensberger’s conviction were illegal and calling the justice system in that county “corrupt.”

In addition to that letter, Lambert also provided a four-page handwritten affidavit from Raffensberger in which he swears Kenneff confessed to tampering with evidence in the Lambert case.

The panel was not persuaded.

“[Lambert's] allegations of prosecutorial wrongdoing have been reviewed and rejected by the previous PCRA court, by this court, by the District Court for the Eastern District of Pennsylvania, and by the Third Circuit,” Senior Judge Eugene Strassburger wrote in a nine-page opinion. “Every specific allegation of prosecutorial misconduct contained in the Raffensberger affidavit has already been addressed, including: the significance of the earring and/or earring back found at the scene of the murder, the plausibility of the victim’s ‘dying declaration’ that [Lambert] was her killer, the alleged swapping of evidence, specifically a pair of black sweatpants, and the allegation that appellant was framed in order to cover up a rape by police officers.”

Rather than touching on the merits of each of Lambert’s allegations, Strassburger simply added a footnote next to each claim, leading readers of the opinion, if they choose, to five court documents all captioned Lambert.

But the judge who first presided over Lambert’s highly-scrutinized trial has picked apart Lambert’s claims in turn.

In a 329-page opinion that exonerated the police and prosecutors she accused of misconduct and blasts the federal judge who declared her “innocent” and set her free, Judge Lawrence Stengel (now of the U.S. District Court for the Eastern District of Pennsylvania) found that, of the 257 claims raised by Lambert’s lawyers, many “have more sensational appeal than legal merit.”

The bottom line, Stengel said in the 1998 opinion on Lambert’s first PCRA petition, is that Lambert’s claim of innocence rests on her own credibility — and she has none.

Prosecutors from the Lancaster County District Attorney’s Office did not return a call requesting comment.

Lambert is currently serving a life sentence. It was unclear if she intended to seek review from the state Supreme Court — seemingly her last move in more than 20 years of appeals.

Ben Present can be contacted at 215-557-2315 or bpresent@alm.com. Follow him on Twitter @BPresentTLI. •