Yvonne Frederiksen was scared, and she let prison officials know. Her cellmate, Veronica Lewis, was notorious: She'd been shuffled between prisons and psychiatric hospitals after she shot and nearly killed her gun range instructor in 2015. Lewis' case had been the subject of political and legal debate about how the state should treat people who have serious mental illness and a history of violence.

The two had been roommates in the Echo unit at Vermont's only women's prison for a few weeks when, in late May, Lewis' behavior seemed to change. Frederiksen, 52, said Lewis, 40, threatened her and began to express unusual fears, saying, at one point, that prison officials were going to kill her and dress her corpse in a clown suit.

"Nothing is being done about it!" Frederiksen wrote in a formal grievance that she filed on May 27 and later provided to Seven Days.

Prison officials dismissed the grievance as "unsubstantiated." Then, on May 29, police say Lewis attacked Frederiksen as she slept, bludgeoning her head with a prison-issued tablet computer and a padlock tucked inside a sock.

Frederiksen was taken to the hospital, diagnosed with a brain contusion and given stitches for a head wound. Last week, she was released from prison on house arrest. Lewis is due to be arraigned on a charge of aggravated assault on August 1.

The attack, details of which were previously unreported, raises questions about whether Vermont prisons are equipped to meet the needs of someone like Lewis — and whether staff can keep other prisoners safe.

Though an internal review has not yet begun, the Vermont Department of Corrections defended its handling of the incident, asserting that prison workers did not miss signs of a mental health crisis in Lewis and properly vetted Frederiksen's grievance. Despite an ongoing staffing shortage, Commissioner Nick Deml said officers intervened quickly once they heard inmates' screams for help. That's even though a single officer was covering two units and was in the other one when the attack occurred.

It's not the first time a mentally ill inmate has beaten a cellmate. In December 2022, Mbyayenge "Robbie" Mafuta critically injured 55-year-old Jeffrey Hall at Northwest State Correctional Facility in St. Albans. Mafuta, then 21, had been given a special designation for inmates with serious mental illness and was on suicide watch days before the incident. Hall later died of his injuries.

Frederiksen, who was jailed for violating parole after a DUI conviction, has been plagued by headaches and vision problems since her release from the hospital. She remembers nothing of the attack, just the feeling of "freaking out" as she was strapped to a stretcher. She said she intends to sue the state for failing to protect her. Frederiksen maintains that prison is not the right place for Lewis.

"I'm fighting for her to be put in a mental institution for the rest of her life," Frederiksen said in an interview. "I don't want her to hurt anyone else."

Lewis has confounded Vermont officials for years. Born in Queens, N.Y., she studied political science at Long Island University until her mental health deteriorated and she began experiencing paranoia and hallucinations, her federal public defender recounted in court proceedings reviewed by Seven Days. She became homeless and lived with violent and abusive men. Lewis attempted suicide and was hospitalized more than a dozen times.

She was living in a therapeutic home in Vermont when she absconded to a Westford gun range where she had arranged for private lessons. She shot her instructor three times and fled the scene before police later caught her.

While awaiting trial at the Chittenden Regional Correctional Facility, Lewis racked up six assault charges. She threw urine at correctional officers and brutally attacked a psychiatrist who was hired to evaluate her mental state. A judge deemed Lewis incompetent to stand trial and sent her to the Vermont Psychiatric Care Hospital for treatment, where her condition improved.

In 2019, Chittenden County State's Attorney Sarah George dismissed all of the cases against Lewis after an expert concluded she was insane when she committed the crimes. That left Lewis in the care of the Vermont Department of Mental Health, which likely would have released her to community-based treatment at some point.

Gov. Phil Scott publicly called upon then-attorney general T.J. Donovan to refile criminal charges. He did — and the U.S. Attorney's Office filed new charges against Lewis, too.

In 2021, Lewis took a complex plea deal that included 10 years in prison, with 10 more suspended, plus 40 years on probation. She received credit for time served and, before the attack, was scheduled to be released in October 2024.

From 2017 until May 2024, Lewis had no serious disciplinary problems in prison. At a 2021 court hearing, her attorney attributed her improvement to proper levels of medication. She had been living in the Echo unit of the women's prison, a less restrictive place for inmates deemed lower risk.

Her good behavior and apparent mental health improvement factored into her placement in a privileged unit, Deml said in an interview last month. He credited such programs for contributing to the state's lower-than-average rates of inmate violence. Units that use restorative justice principles, Deml said, "allow people to have a little more agency in their daily life."

Yet there were indications that Lewis was distressed in recent months. In late April, about a month before the assault, she mailed a handwritten letter to a state judge who had presided over parts of her criminal cases.

In the letter, obtained by Seven Days, Lewis wrote that she felt unsafe at the women's prison, where she had "a history" and still experienced "the trauma from that last experience."

She told the judge that she wanted to return to the Vermont Psychiatric Care Hospital in Berlin to complete the remaining five months of her prison sentence. She noted that she had "been doing very well and made strides in my recovery and would like to continue on that path."

"I have coping skills," she wrote, but things were "very difficult" in the "high stress environment."

"Please take what I am saying into consideration," Lewis wrote. "You can contact me by mail. Please keep it confidential, and put confidential on the return letter for I do not trust the people here.

"I think they are planning and trying to sabotage all my hard work and effort that I worked so hard to build," she concluded.

The letter was attached to her criminal court case file, but corrections officials say they were not aware of its contents.

Frederiksen said she and Lewis had gotten into a disagreement about a week before the assault. Frederiksen had said something about a movie, and Lewis interpreted the remark as racist. After that, she said, Lewis would say things such as, "I'm going to hurt you really bad," then, an hour or so later, say "I hope you're not scared."

"She quit going to the gym," Frederiksen recalled. "She quit going to the dayroom and watching movies."

Frederiksen told officers of her concerns and later filed a formal grievance. Prison staff, she wrote, seemed to think her concerns were "a joke."

There was nothing particularly unsettling about the evening before the assault, Frederiksen said. The two watched TV in their cell, laughing at the game show "Password."

Just before 5 a.m. on May 29, a prisoner in the cell next to them awoke to the sound of Frederiksen screaming, "Help me!" Security video from the unit shows Lewis peered toward the officer's desk — which was vacant because of a staffing shortage — before she draped a towel over herself "like a bib" and attacked Frederiksen, according to Vermont State Police.

The neighbor went to the cell and saw Frederiksen on the floor while Lewis was hitting her in the head. It was a "bloody nasty scene," she later told a state police investigator. She told a fourth inmate to get help, and that woman ran through the dayroom to find a correctional officer.

The officer on duty, identified as Melissa Dix, was covering two units because the prison didn't have enough staff that day. As the attack unfolded, Dix was in the other unit, on the phone with a supervisor discussing the staffing shortage, according to internal incident reports that Seven Days obtained.

Dix arrived seconds later, by which time Lewis had left her cell and was walking around the unit, according to a police affidavit based on a review of security video.

Staffing shortages have been a yearslong problem in the Department of Corrections. The number of vacancies peaked during the pandemic and has since dropped by half, but shortages remain. More than 18 percent of positions at the women's prison are vacant, above pre-pandemic norms.

Dix's multiunit assignment that morning was "not uncommon," corrections spokesperson Haley Sommers said in an email, "and has, to date, not presented any issues to safety, especially during the sleeping hours."

A current prisoner on a different unit at Chittenden Regional Correctional Facility told Seven Days that women there frequently have recreational time curtailed because of staffing inadequacies. Deml, appointed in 2021, implemented a new staffing pattern that is meant to help with the problem. But Vermont State Employees' Association executive director Steve Howard said the system doesn't work when corrections lacks enough employees.

"This is just a cruel and inhumane way to treat the men and women on the front lines," Howard said of the ongoing staffing shortages.

Lewis was placed in segregation following the May beating, according to department records filed in court. She tried to contest the discipline, claiming she was not in a right state of mind when she attacked Frederiksen. "Thought she was still dreaming," an internal report referenced in the police affidavit states.

Lewis later appealed the discipline and then filed a lawsuit, still pending, that asked a judge to intervene. She wrote in the appeal paperwork that a fellow inmate could testify to her "mental health deterioration." Lewis' assigned counsel in the state Prisoners' Rights Office didn't respond to an interview request. Lewis could not be reached for comment.

Attorney General Charity Clark's office — not State's Attorney George — will prosecute the new aggravated assault case against Lewis. George didn't decline to pursue criminal charges, she said in an email. Rather, George said, Clark's office asked to take the case.

Already, Lewis faces a separate charge of violating the terms of her probation. Her probation officer, in a recent court filing, asked a judge to revoke the 10-year suspended portion of her plea deal.

If that happens, Lewis may well remain in the women's prison for many years to come.