A former Philadelphia prosecutor who recommended that a man’s murder conviction be overturned said she did so at the direction of her boss — who she said had done no meaningful review of the evidence and instead was “colluding” with defense attorneys to find the most effective way to have the case thrown out.
While testifying at a unique hearing Friday in federal court, former Assistant District Attorney Jaclyn Mason said supervisors in the district attorney’s office had effectively abandoned their responsibility to independently investigate Dennis Johnson’s appeal and determine if he should be freed from prison.
Instead, Mason said, her supervisor, Matthew Stiegler, held routine meetings with Johnson’s lawyers, including the Federal Community Defender Office and the Pennsylvania Innocence Project, to strategize the most effective paths to secure Johnson’s release. And neither she nor Stiegler reviewed key evidence in Johnson’s case, she said, including trial transcripts, homicide files, or witness interviews.
“Matt told me: ‘If it’s good enough for the Innocence Project, it’s good enough for me,’” Mason said.
Just as strikingly, she said, earlier this spring, when it became clear that that process might be exposed in court, another set of supervisors asked her to lie to a federal judge.
As Mason recalled, the supervisors were worried that if the judge found out the full extent of the office’s actions in the case, it would exacerbate the already intense public scrutiny the office was under for the way it had acted in other murder appeals.
According to Mason, the supervisors suggested she simply tell the judge that any mistakes in the case were hers, and hope that that would be enough to avoid a more thorough inquiry.
Mason said she declined and resigned.
“I said, ‘I’m not going to go to court to lie to protect the district attorney’s office,” Mason said. “How come telling the truth isn’t an option?”
The extraordinary testimony came as part of Johnson’s appeal, which has taken an unusual path through the courts and remains pending before U.S. District Judge Paul S. Diamond.
It also served as the latest chapter in a series of developments that have raised questions about one of District Attorney Larry Krasner’s key policy initiatives: his office’s willingness to review old convictions and seek to overturn those that prosecutors believe were marred by legal problems.
Just last month, the Pennsylvania Supreme Court ruled that Krasner’s office had misled judges so consistently and flagrantly in appellate matters that moving forward, any time his office recommends that a conviction be overturned, the state attorney general must be brought in to review the matter as well.
Diamond was also involved in disciplining two top supervisors in Krasner’s office in recent months, finding that they had been “misleading and dishonest” while seeking to overturn an inmate’s death sentence.
Krasner has made post-conviction review a central part of his reform-oriented agenda, touting the fact that his office has helped free 59 people — mostly Black men — from what he’s called wrongful convictions.
But judges in both state and federal court have raised pointed questions in recent months about whether Krasner’s office has been sloppy or even intentionally misleading while seeking to advance that agenda.
And during Friday’s hearing, Diamond expressed occasional bewilderment at some of Stiegler’s admissions on the stand — including that while he led the office’s Federal Litigation Unit, his staff generally did not reinterview witnesses or speak to previous prosecutors before deciding whether to recommend that a conviction be overturned.
“It’s a smorgasbord of error — and we’re just gonna pick one?” Diamond asked.
A ‘pawn’ in a preordained process
The case around which Friday’s hearing was nominally centered was Johnson’s conviction for second-degree murder.
In 2009, a jury found him guilty of fatally shooting Kenyatta Smith during a robbery outside a North Philadelphia convenience store two years earlier. He was sentenced to life in prison.
Johnson appealed, in part because he said his trial lawyer was ineffective.
And in 2022, Mason filed court documents agreeing with that assertion — and saying the error was so pronounced that his conviction should be thrown out.
“The case against Johnson was not overwhelming from the outset and his counsel was constitutionally ineffective,” Mason wrote. “The post-trial investigation unearthed additional factors that highlight weaknesses in the prosecution and confirm a low level of confidence in the outcome of Johnson’s trial.”
In court Friday, however, Mason said she was effectively doing Stiegler’s bidding when she filed that brief.
She’d only been in the office for about four months when Stiegler assigned her Johnson’s case, she said. And she’d never before worked as a prosecutor or handled similar federal appeals.
The office also gave her close to no training, she said. And from the moment she was assigned Johnson’s case, she said, she got the impression that Stiegler knew how he wanted the matter to go.
“The decision to concede had been made, and then I was his pawn,” she said. “I was his scribe.”
In the months that followed, Mason said, she and Stiegler did almost no independent examination of the evidence in Johnson’s case. But they did have meetings with Johnson’s attorneys, she said, at which the two sides sometimes collaborated on legal strategies for how to ensure his petition would succeed.
When Mason did actually draft the brief supporting the appeal, she said, Stiegler offered edits — all of which made it into the document. Another supervisor, Nancy Winkelman, the onetime head of the Law Division, also made suggestions that were included in the final brief, Mason said.
Stiegler testified Friday as well, and said he believed that when Mason was assigned the case, she would review it and provide her best assessment to him. That review, he said, was expected to include an examination of key evidence, including trial testimony or witness statements.
But under questioning by Diamond, he acknowledged that his unit at that time did not regularly reinvestigate cases, either by re-interviewing witnesses or reexamining primary evidence — an admission that seemed to baffle the judge.
“You did no investigation on your own?” he asked at one point.
“No,” Stiegler replied.
As for the decision to agree that Johnson’s conviction should be overturned, Stiegler said: “My recollection is it was a collaborative decision between Ms. Mason and me.”
But Mason said that wasn’t true.
“He met and conferred with the Federal Defender and the Innocence Project to decide how it was going to go before it was assigned to me,” she said.
A sudden resignation
Still, none of that discord surfaced until this spring, when Diamond — who will ultimately decide whether to overturn Johnson’s conviction — scheduled an evidentiary hearing. At the time, he said he wanted to hear from several key witnesses to evaluate the strength of the evidence against Johnson.
He also asked the attorney general’s office to review the case, apparently wary that the district attorney’s office was simply agreeing with Johnson’s lawyers.
At that point, Mason said, a set of different supervisors in the Law Division “started to panic.”
And after she told them the “collusive” manner in which the appeal had been handled, she said she was told, in essence, to fall on her sword.
As Mason recalled it, the supervisors told her to tell Diamond that any mistakes in the office’s brief were hers, “and if we do that, the court might get angry, but it won’t find out how this concession got put together — which is what we really want to avoid.”
“The whole goal [was] that the process by which that concession came to be not be revealed,” Mason said.
Within days, Mason said, she resigned.
A few days after that, the supervisors in the Law Division — David Napiorski, Steven Wildberger, Peter Andrews, and Katherine Ernst — filed a motion with Diamond seeking to undo the position that Mason and Stiegler had once recommended, saying the pair’s brief had been based on “material misstatements.”
Mason said she was “blindsided” by that filing, and that she believed she was being used as a scapegoat to protect the office and its actions in the case.
“The whole scheme was designed to cover up how that brief was put together,” she said.
Friday’s hearing ended before the supervisors she accused of wrongdoing had time to testify or respond to her assertions. Diamond said he would schedule another hearing to hear from them.
Johnson’s fate also remains undecided with the legal issues unresolved.
Stiegler, meanwhile, denied that he’d pushed Mason to take a specific position in the case, or that he’d had improper interactions with Johnson’s defense lawyers as the office worked on the appeal.
Mason was definitive in her view of Stiegler’s testimony.
“Nothing Matt said was true,” Mason said. “Nothing he said was true.”
