HELENA - Thirty years to the month, Dianna Lewis shot and killed her dad and stepmom while they were asleep, believing they were part of a militia that was trying to kill thousands of people, including herself.
She was back in the very same courtroom on Friday where she had pleaded guilty, facing the prospect of having her suspended sentence revoked.
Watch: Woman who killed her parents 30 years ago has parole revoked
The murders of Peggy Parmalee Lewis and Rob Lewis took place on September 22, 1995.
Two years later, Lewis used an Alford plea and was sentenced to 80 years for committing two counts of mitigated deliberate homicide, which, according to Montana law, is when someone "purposely or knowingly causes the death or another human being...but does so under the influence of extreme mental or emotional stress for which there is reasonable explanation or excuse."
Up until 2013, Lewis lived at the Montana State Hospital in Warm Springs, but that year, a judge ruled for her to be released to a residential care facility in Billings.
Three years after that, her release was revoked for not following her court-ordered requirements. She was sentenced to 60 years, with 50 suspended, spending at least one year at a pre-release center.
She was granted parole again in 2022, but last week, she again appeared in court for a hearing to revoke her suspended sentence, which could lead to the termination of her parole depending on the judge's ruling.
On Sept. 12, Lewis appeared in Judge Michael McMahon's courtroom for a petition for revocation of suspended sentences on two counts — one for a failure to remain law-abiding and the second for a failure to comply with the medication treatment regimen.
The Broadwater County Attorney's Office called multiple witnesses who had recent interactions with Lewis, including Tyler Reitz, a deputy sheriff with the Yellowstone County Sheriff's Office.
He encountered Lewis in April of this year, on I-90 between Billings and Laurel. She was walking on a median around 3:30 a.m., and when Reitz approached, he says she began walking in the middle of the interstate.
"She continuously talked about how god loved her, she loved god, she didn't need any assistance from law enforcement, and that basically we were all evil," he said.
Detention center staff from three different counties also testified.
"We couldn't trust from minute to minute what she was going to be like," said Broadwater County Detention Center Officer Sarah Peeler.
They said she often refused to take her medication, including a mood stabilizer or anti-psychotic.
Lewis, who was born in the United States, said that she would like to be deported.
"I don't have to put up with this," she yelled. "I want to go home. I always have wanted to go home. I don't belong here. When do I get to go home?"
Judge McMahon found that the state proved both counts — not remaining law-abiding and not taking her medication.
Lewis's sentencing will be held on November 14, 2025.
For those close to the case, hearings like this can take them back to the day of the murder. MTN spoke with someone who reported on Lewis roughly a decade ago and with the daughters of Peggy Parmalee Lewis, who are still looking for justice thirty years later.
"It feels like day one again," said Barb Thomas.
She and Susan Graham are the daughters of Peggy Parmelee Lewis and stepdaughters of Rob Lewis.
"You never left a room without her saying, 'I love you.' He was a special guy that was just so full of laughter and love," Thomas said about her mom and step-dad.
Graham and Thomas have attended hearings and sentencing over the last few decades.
The two are both now older than what their mom and step-dad were at the time of their murders.
"It's hard to remember Mom and Rob as the persons and not the crime," Thomas said.
To keep their memory alive, the family put together a traveling memorial for Peggy and Rob that honors crime victims and can be used by judges and law enforcement.
Another person who has followed the case is Eve Byron, who reported on Lewis's hearings back in the 2010s.
We asked her about how it felt to hear the name Dianna Lewis after all these years.
"I thought 'Oh my goodness, here she goes again'," said Byron.
Byron says she isn’t surprised to hear Lewis was back in court, with the hearing from Friday being what family members like Graham and Thomas have warned about.
“It’s almost as though they foreshadowed the events that are happening today.”
Over the years, Byron has covered numerous stories about mental health in Montana and other criminal cases where mental health was a significant contributing factor.
"All too often, I think that our society fails people and we don't give them what they need for whatever reasons," noted Byron.
The Montana State Hospital in Warm Springs, the Treasure State's only state-run psychiatric hospital, has come under scrutiny in recent years, with the state’s behavioral health system facing an array of problems.
At state public meetings, critics have voiced complaints about a lack of consistent leadership, severe understaffing, and not having the adequate resources to treat patients. In 2022, the state hospital lost its federal certification due to patient deaths and other "inadequacies."
Montana lawmakers and Governor Greg Gianforte have called for an overhaul and improvement to the Montana State Hospital and the state's behavioral health systems.
In 2025, the state legislature invested $124 million in state spending and up to $40 million in federal funds over the next two years to improve the state hospital and other behavioral health programs. Governor Greg Gianforte is also directing the state to create a second state hospital in Billings for $26.5 million.
