It’s a routine night at Edmonton’s maximum-security prison until the guards reach the Solitary Unit. The time is 9:11 and the two guards are making their tedious hourly rounds. As long as they ignore the zoo-pen odour of the seg unit, it is a straightforward task: peer through a narrow cell window, make sure the inmate looks okay, move on.

But near the end of the range, something gives them pause. The window of one cell’s light pink door is papered over, a common inmate trick to protest against some perceived injustice or to hide something nefarious.

The guards usually paid little attention to the prisoner inside, Edward Christopher Snowshoe, and he usually returned the favour: Withdrawn and lethargic, he refused to speak with psychologists, take his allotted hour of daily recreation time, or attend monthly meetings where he could argue for a transfer. There were rules to ensure the close monitoring of segregated inmates, but nobody on the floor could say for sure how long Mr. Snowshoe had been confined to his cell, its dimensions roughly equivalent to those of a Volkswagen Beetle.

The guards knock on the metal door and call Mr. Snowshoe’s name. Hearing nothing, one of them opens the food slot and looks inside with a flashlight.

Three years in a federal prison had turned Eddie Snowshoe into a student of death. He had tried suicide four times before – by hanging, slashing, and both in succession. Nothing worked. His brain’s survival instincts would always foil his deadly intentions: His legs would seek purchase on the cell floor to relieve the pressure of his makeshift noose, or his hand would reach as if involuntarily for the cell’s call button. On this summer night, he would defeat his body’s reflexes with dandruff shampoo.

Through the food slot, the guard sees Mr. Snowshoe slumped in a corner, a braided bedsheet looped around his neck and tied to a shelf. One guard remains at the door while the other rushes to alert a superior and retrieve a hooked knife kept specifically for this purpose. One minute passes before three officers unlock the cell and crowd in.

Mr. Snowshoe’s bare feet have turned a bluish-purple. The floor is slippery. One officer lifts Eddie’s torso, all 5-foot-8 and 170 pounds of it; another cuts the sheet. They can’t find a pulse. They begin CPR.

A defibrillator appears, but it returns an ominous reading: “No shock advised.” They attach a second defibrillator, get the same response.

At 9:33, three paramedics arrive. The cell Mr. Snowshoe has endured for 162 days proves too cramped for the personnel necessary to save his life; they drag him into the hallway. The guards continue their furious pumping of his chest. For all the faults that preceded this desperate moment, there is no questioning the guards’ resolve to save the young inmate that night. But after nearly an hour of life-saving efforts, they must pronounce Edward Christopher Snowshoe dead. He is 24 years old.

His was a death foretold. Over three years in prison, Mr. Snowshoe had morphed from a shy but hale young man into a chronically suicidal inmate suffering from a dangerous brew of mental-health issues. He died – on Aug. 13, 2010 – while locked in a 2.5-by-3.6-metre cell where the Correctional Service of Canada had determined he posed the least amount of harm to himself or others.

But as libraries of stats and scholarly articles can attest, solitary confinement is a counterproductive kind of harm prevention. Humans are social animals. We subsist on stimulus and response. To restrain us alone is to deny stimuli; correspondingly, our response mechanisms break down. In solitary, this can lead to a litany of health problems – including, but not limited to, hallucinations, anxiety, loss of impulse control, severe depression, heart palpitations and reduced brain function. In many cases, the damage is irreversible. It’s no wonder the suicide rate in federal prisons is seven times that in the public at large, with nearly half taking place in segregation.

In the United States, officials are responding to the mounting body of evidence on the dangers of solitary by weaning prisons off the practice. In Mississippi, solitary admissions are down by 75 per cent since 2007. Maine, California and other states are following suit. The trend is international in scale. The UN Special Rapporteur on torture has stated that solitary confinement is “contrary to one of the essential aims of the penitentiary system.”

In Canada, though, the use of solitary continues unabated. Officials have tinkered with solitary policies in the wake of several high-profile suicides, but the number of federal inmates in segregation here creeps ever upward – by more than 6 per cent over the last five years alone. One year ago, a coroner’s inquest into the death of Ashley Smith, the New Brunswick teen who took her life while in Correctional Service custody in 2007, recommended strict limits on solitary confinement: a maximum consecutive stay of 15 days, and a cap of 60 days in solitary for every calendar year. The Correctional Service has yet to respond.

The proposal was hardly new. In 1996, then Justice of the Ontario Court of Appeal Louise Arbour led a landmark investigation into a riot at the Prison for Women in Kingston that endorsed a similar 60-day cap. The Correctional Service now conducts mandatory reviews of every segregated inmate’s case file after five days, and then at 30-day intervals.

But there is no cap on time in solitary, and, it seems, little government will to impose one. “If we found out that animals in a Humane Society were being caged in circumstances where they were losing their sanity, injuring themselves, killing themselves, society would respond in a very heartfelt way,” says Catherine Latimer, executive director of the John Howard Society of Canada, which advocates for prisoners’ rights. “I can’t imagine why the response is any less with humans involved.”

Although he died in 2010, Eddie Snowshoe is a relatively new character in the saga of modern Canadian corrections. His name came to light only after Alberta conducted a public fatality inquiry earlier this year. His plight, like Ms. Smith’s, tells a broader story about the roughly 1,800 Canadian inmates languishing in provincial and federal solitary cells on any given day. In some prisons, as many as half of those inmates exhibit mental-health problems, straining an agency built to incarcerate criminals, not to treat illness. An abstract impression of Mr. Snowshoe’s final years exists in court documents, prison reports, and hazy memories. They answer much about him, but raise many more questions about why a death forewarned was not a death averted.

Many of those questions will go unanswered. The Correctional Service of Canada was unco-operative during the reporting of this article, citing a host of reasons involving security and privacy. It has been similarly unresponsive to the federal-prison ombudsman, Howard Sapers, who has long urged the agency to introduce a ban on placing inmates with mental-health or suicide issues in segregation. “That recommendation has not been accepted by the Correctional Service of Canada,” Mr. Sapers says.

In Mr. Snowshoe’s case, the inmate in solitary became as apathetic and ornery as a lion in a roadside zoo. He lay for hours in bed, plotting how to overcome his brain’s survival mechanisms. Investigators would discover that the slippery substance on the floor that night was Head & Shoulders shampoo, strategically deployed to prevent his flailing feet from gaining traction.

After prison officials handed over the suicide scene to Edmonton Police, investigators found a note written in neat, black ink. Its brevity suggests a young man in a hurry, thoughts focused on the task at hand: “I want all my personal proport [sic] to be trashed. Tell my mother that I have no blame at all towards her and that I know she will be strong for the boys.”

The night before Mr. Snowshoe landed in jail, the sun slipped behind the snow-covered Richardson Mountains overlooking Fort McPherson, NWT, at 7 o’clock. In the darkness, Mr. Snowshoe saw his chance. He was born here on Nov. 11, 1985, knew all the area’s potholes and mountain trails, bootleggers and dope dealers. It was a place he felt both protected and entrapped.

Around 10 p.m. on that final night of February, 2007, Mr. Snowshoe tucked a black pump-action .22 rifle inside his parka, and stuffed two knives, a pair of latex gloves and several lengths of rope into his pockets. He gathered 11 bullets and stepped out the back door of the family’s government-owned home and into the minus-30 night air. His mother, Effie Bella Snowshoe, heard the door creak. When she found it slightly open, she assumed her eldest son would be right back.

Mr. Snowshoe hitched a ride north. One hour into his journey, the Dempster Highway crossed the Mackenzie River. Twenty years earlier, Mr. Snowshoe’s father had been working on the ice road around this spot when his bulldozer plunged through the ice. Rescuers found the dozer, but the Mackenzie never surrendered its driver. The community had held a memorial service around the ice hole where he had been last seen alive.

The spot served as a reminder of why Mr. Snowshoe was in such a jam. From an early age, he had taken on the “role of keeping the family together,” wrote Connie Morgan, a family friend, in a letter used as a character reference during his court case. He worked hard to fill the paternal void by serving as protector and disciplinarian to his three younger brothers. Their successes filled him with pride, and their missteps brought shame.

And the Snowshoes had their vices. Court documents from 2007 refer to Ms. Snowshoe’s “alcohol problem,” though she insists she’s now sober. At least once, she’d fallen so far behind on rent that the town housing authority went to court to evict her. Mr. Snowshoe had his own checkered past. There were two theft convictions as a youth, two break-and-enter convictions as an adult. Since 2004 he’d been clean, at least as far as any judge knew.

His breaking point came one day in 2007. Mr. Snowshoe’s mom caught one of her younger sons exhaling cigarette smoke, so she swatted the boy with a bag; she says it was a soft strike. A neighbour viewed the scene differently and picked up the phone. The next morning, a child-services worker arrived on the Snowshoes’ doorstep. Effie Bella’s two youngest boys wound up in government care.

Mr. Snowshoe, man of the house, was angry and humiliated. Even after a month had passed, the resentment remained: This trip down the Dempster, a modest arsenal weighing down his coat, was his apparently irrational reaction.

Ms. Snowshoe woke the next morning with an unsettled feeling. She remembered the open door and sprang from bed. Her family history of death and disappearance fuelled her sense of urgency as she padded down the hall to Mr. Snowshoe’s room. “His bed – it wasn’t even slept in,” she recalls.

She began dialling phone numbers in search of Eddie. As in many isolated communities, the local radio station in Fort McPherson, CBQM, acts as an informal “moccasin telegraph” broadcasting local news, games and personal messages from listeners to its entire network. Effie Bella put out a message asking anyone who’d seen Eddie to call her. The phone rang moments later – a local girl relaying a rumour that Mr. Snowshoe was in Inuvik, nearly 200 km north of Fort McPherson.

The call sent his mother into a panic. “Why the hell would he go to Inuvik?” she thought.

Around 9 a.m., Mr. Snowshoe pulled a neck-warmer over his face, so that only his brown eyes were visible, and called Delta Cabs to pick him up along Inuvik’s main drag. A minute later, car No. 20, a Ford Crown Victoria, rolled up with 21-year-old Kelly El Khatib at the wheel. Eddie was careful to hide the rifle as he stepped in and directed Mr. El Khatib to the airport, 13 km away. Court documents recreate their exchange.

For the Arctic, Mike Zubko Airport is a busy hub. At least four airlines operate scheduled passenger flights, providing a far quicker means of leaving town than the long, jaw-rattling Dempster. Every local cabbie has the flight schedule memorized. Early in the trip, it occurred to Mr. El Khatib that the airport would be dead for at least three hours – aside from the faithful breakfast crowd at the Cloud 9 Cafeteria attached to the main terminal. When the cabbie told Mr. Snowshoe as much, he got a curt response – it was clear Eddie wasn’t interested in greasy eggs.

“Ten, Whitehorse flight,” he said.

Something about the tone told Mr. El Khatib not to argue.

Within a couple of minutes, they were clear of town and its single traffic light. It was time. Mr. Snowshoe pulled the .22 from his parka and pointed the barrel at the petrified driver.

“What do you want?” Mr. El Khatib shouted.

“The car,” Eddie said.

He ordered Mr. El Khatib to hang a right down Shell Lake Road, out of sight of any homes. Half-metre-high snowbanks lined the road; scrub pines leaned beneath a recent dusting of snow. Mr. El Khatib peered nervously into his rear-view mirror, and so Mr. Snowshoe pushed it sideways with the rifle barrel. Then, he noticed Mr. El Khatib clicking his CB radio, a furtive way of alerting a dispatcher. Mr. Snowshoe lost it. He shot a round into the car’s dashboard, leaving a small hole just above the glove compartment. He then yelled at Mr. El Khatib to step out of the cab and lie face-down on the icy road: He would use the rope to tie up the cabbie before throwing him in the trunk – at least that was the plan.

As Mr. El Khatib opened his door, though, he pushed the automatic locks and sprinted away. Mr. Snowshoe went for his rear-door handle, but it wouldn’t give; like a police cruiser, cab No. 20 had no unlocking mechanism in the rear. Rather than let the driver escape, Mr. Snowshoe raised the barrel to the back window and squeezed the trigger.

The slug caught Mr. Khatib just above the right hip. A red stain spread across his sleeveless undershirt, but he kept running, flagging down a welder who happened to be driving by. Mr. Snowshoe, meanwhile, freed himself from the car and surveyed his situation. The cabbie would certainly alert the Mounties as soon he got downtown, a matter of minutes. Mr. Snowshoe reached for a thin wad of bills near the driver’s seat. This would be all he had to show for his efforts: $45.

Rather than flee home, he drove the Crown Vic toward Inuvik. The logic of his plan was never sound, and now it was unravelling. When he tried to evade an RCMP cruiser, he slammed the car into a snowbank. He stepped out with his hands raised in surrender. The whole episode had taken 35 minutes.

“I was prepared to get caught. My life was going nowhere anyway,” Mr. Snowshoe told the arresting officer, who began reading him his rights. “I don’t wanna call a lawyer,” he said. “I was caught red-handed. It was either that or kill myself. My life was going nowhere.”

The police called his mother and asked if she had a son named Edward Christopher Snowshoe. She broke down crying when the conversation ended.

Mr. Snowshoe admitted everything, even offered to walk investigators through the crime, frame-by-frame. “It wasn’t a very well-thought-out crime, which is typical of crime up here,” says Mr. Snowshoe’s lawyer, Michael Hansen. “I’m not even sure he knew why he did this, except funds were tight at home and he considered himself the man of the house. That was very important to him. This was his misdirected way of trying to provide for his family. He might have been looking at more time if he had not been co-operative, not been youthful, not been aboriginal. The lack of sophistication all played into getting a reduced sentence.”

The judge gave him five years. He recommended Mr. Snowshoe upgrade his Grade 10 education and supplement it with anger-management classes, a requirement that would necessitate time in a bigger, southern prison.

“Despite the seriousness of this offence, the Court should not and society should not give up on Mr. Snowshoe,” Justice Virginia Schuler said in her decision. “Unfortunately, Mr. Snowshoe seems to have faced the problems that a number of young people face in the small communities and also the larger ones of the Northwest Territories; a difficult family life, alcohol abuse in the home, little education, lack of a job and other opportunities, and I do take that into account. At the same time, Mr. Snowshoe’s reaction to those problems is alarming and indicates to me that he has some very serious issues to deal with.”

In June, 2007, Mr. Snowshoe arrived at Drumheller Institution in Alberta, a 40-year-old medium- and minimum-security penitentiary capable of holding 600 inmates – nearly the population of his hometown.

The Correctional Service of Canada conducts an impressive battery of assessments when inmates begin a prison term: mental-health screening, a nursing assessment, a preliminary evaluation with a parole officer. With Eddie, they added an aboriginal-social-history evaluation and a few other tests assessing his fitness for incarceration. Staff noted that he was a polite, quiet young man with no known history of violence or mental-health issues.

Still, there were a few niggling concerns. One psychologist suggested he had adjustment disorder, “characterized by anxiety, impairment in functioning and reckless decision making when faced with situational stressors.” The diagnosis is common among aboriginal inmates uprooted from small, insular communities and dropped among a large population of hardened criminals. Mr. Snowshoe was accustomed to open spaces and familiar faces. This was like landing on the moon.

Even so, his first few months of incarceration were unexceptional. In October, Corrections transferred Mr. Snowshoe to Stony Mountain Institution, a medium-security prison just north of Winnipeg with robust aboriginal programming.

His early interactions with other inmates proved difficult. Staff noted he was “paranoid and vulnerable,” according to an internal Correctional Service report. “He needed to feel that someone cared about him in order to be able to cope.”

Mr. Snowshoe’s next act seemed out of character for him, but is consistent with the statistics: In the two decades since 1994, the Correctional Service recorded 211 suicides in custody, making it the leading cause of death among inmates, when natural causes are excluded.

That susceptibility ramps up considerably in the first 90 days of an inmate’s incarceration in a new institution, according to the Office of the Correctional Investigator, which acts as a prison ombudsman’s agency. Twenty-eight days into his term, guards on a routine range walk saw Eddie slumped in a cell corner. They rushed in to cut a ligature around his neck, and saved his life.

By now, there was clear evidence suggesting serious mental-health concerns. Staff took the necessary precautions, placing him on suicide watch after the hanging attempt and subjecting him to another round of testing that resulted in diagnoses of depression and attention deficit hyperactivity disorder. A doctor prescribed Seroquel, a powerful antipsychotic used to treat schizophrenia and severe symptoms of bipolar disorder, as well as the antidepressant Wellbutrin.

At first, Mr. Snowshoe seemed to rebound from the suicidal episode. He worked as a cleaner for eight months. In early 2008, staff made note of his good behaviour after he completed the In Search of Your Warrior Program, a violence-prevention course for aboriginal inmates, and participated in a number of prison-sanctioned sweat lodges. He even enrolled in a school program, but his attendance was poor and he dropped out.

His recovery was so dramatic that staff transferred him to the O-Chi-Chak-Ko-Sipi Healing Lodge. One of eight such lodges on the Correctional Service roster, the minimum-security facility is operated by the Crane River First Nation 225 km northwest of Winnipeg. The 18 staff members stress the importance of “mental, physical, spiritual, and emotional healing” through the use of aboriginal values, all within tepee-inspired architecture.

It was expected that Mr. Snowshoe, as a member of the Gwich’in First Nation, would feel comfortable with the programming, which was heavy on drumming and traditional dancing. But he found it disorienting. In Fort McPherson, he had been raised on George Jones ballads, old-time fiddling, and jigging. According to investigators, “he did not participate in any activities.”

On Aug. 28, 2008, four weeks into his lodge stay, he placed a dummy in his bed and fled. Staff called police. He was eventually found nearby.

Corrections transferred him back to Stony, but treated him with remarkable leniency, given that he was an escapee. In September, 27 days after returning from the lodge, he tried to asphyxiate himself a second time with a makeshift ligature. He would eventually abandon the effort and report the incident to staff, resulting in another suicide watch.

The pattern was clear to anyone paying attention. “All these behaviours show a gradual, declining trend towards poorer decision-making and acting-out behaviour,” noted a confidential Correctional Service report. Mr. Snowshoe was on a long, slow process of “decompensation,” the term used to describe an organ that becomes overwhelmed by disease or stress and begins to break down. In a prison setting, the organ is the psyche, and decompensation leads to emotional instability, mental deterioration and an inability to handle stress.

Mr. Sapers, the Correctional ombudsman, has stated that federal penitentiaries “are fast becoming the nation’s largest psychiatric facilities and repositories for the mentally ill.” His office has found that as many as 80 per cent of all federal inmates have some manner of mental-health concern and that one in five requires psychiatric involvement.

On Feb. 4, 2009, staff discovered that Eddie had cut himself several times on his arms. While at the hospital getting patched up, he admitted he’d intended to bleed out, but the blood had clotted while he remained conscious, so he reverted to hanging himself. When neither attempt went as planned, he hit his call button.

Eddie’s declining mental health came twinned with repeated institutional infractions that tried staff patience. In late January, 2010, they had moved him from the mental-health wing to the general population for possessing “tattooing paraphernalia.” There, he also attempted suicide, and presented as both lethargic and aggressive when placed on suicide watch.

If prison staff were undecided about whether to transfer this unstable inmate to segregation, an outburst on March 1 – three years to the day since Mr. Snowshoe had committed his crime – made up their minds. The exact nature of the incident is redacted from documents obtained by The Globe and Mail. But according to one internal report, Mr. Snowshoe “brandished a facsimile weapon and threatened officers.” A provincial fatality review conducted in 2014 stated that the suspected weapon was nothing more than a juice box turned inside-out. On March 2, he was finally transferred to solitary confinement. It’s a vicious circle: A troubled prisoner is more likely to be sent to solitary and, in turn, more likely to suffer there. In Mr. Snowshoe’s case, it would prove to be a death sentence.

Mr. Snowshoe isn’t around to describe what life is like in solitary, but James Wigmore is. What he remembers best is those damn pink doors. They were intended to have a calming influence on the sometimes rowdy inmates. “You don’t feel calm when you see pink,” says Mr. Wigmore, who spent 19 months in segregation at the maximum-security Edmonton Institution during his time in Correctional Service custody. “It degrades you. It degrades your mind.”

Mr. Wigmore didn’t know Mr. Snowshoe, but his recollections – combined with decades’ worth of academic research on the effects of solitary – help recreate the experience.

Mr. Wigmore found the size of the cell oppressive. He could stretch his arms out and touch both walls. While at times it was so quiet “you could fart on one side of the unit and hear it all the way on the other,” things could become deafening as unruly tenants screamed for attention, often while tossing belongings and intentionally flooding toilets.

He was entitled to one hour a day of recreational time, but says the privilege was routinely rescinded for reasons falling under the broad rubric of “institutional security.” The recreation pens were small enclosures where inmates could see a snapshot of sky beyond four-metre-high brick walls. “If you can imagine, it’s like standing in the bottom of a well,” says Daren Frick, a former assistant warden at Edmonton.

When gang antagonisms led to fights in a recreation pen, it was carved up into five “dog runs,” each measuring about six by one-and-a-half metres. “No normal person would want to live that way,” Mr. Frick says. “A normal, well-adjusted person in that environment would lose it after a while. For someone with developmental issues to be in that situation, I can’t even imagine.”

Research stretching back decades affirms his view. In the 1950s, University of Wisconsin psychologist Harry Harlow tested the effects of isolation by placing rhesus monkeys in escape-proof enclosures. Within days, most would hunch in a corner, stare blankly, mutilate themselves, and rock in place. Twelve months in the boxes “almost obliterated the animals socially,” Dr. Harlow observed.

In 1951, McGill University researchers designed a human experiment in which male graduate students would spend six weeks alone in small rooms, wearing goggles, earphones and gloves to enhance their sensory deprivation. Not one lasted more than a week, with several suffering from hallucinations.

Stuart Grassian, a psychiatrist and former faculty member at Harvard Medical School, interviewed hundreds of inmates as part of his studies on the health effects of segregation. Before undergoing solitary, nearly all of them insisted that they could handle whatever the guards threw at them. Eventually, the bravado would erode, and subjects would divulge a “strikingly similar” series of symptoms.

More than half had panic attacks and became so hyper-responsive to stimuli that something like the rattling of plumbing would push them to holler in protest. Nearly a third reported hearing voices or seeing hallucinations. Other common symptoms included uncontrollable aggression, difficulty concentrating, paranoia, and problems with impulse control. Together, Dr. Grassian has theorized, these symptoms form a distinct syndrome, a kind of delirium that has proven irreversible in many cases. The research has been cited hundreds of times and held up by opponents of solitary as evidence that the practice is tantamount to cruel and unusual punishment.

Dr. Grassian’s observations echo those of Charles Dickens nearly 200 years ago, at the dawn of the North American penitentiary movement, when solitary confinement emerged as a supposedly humane method of rehabilitating prisoners. In 1829, Quakers and Anglicans made segregation an architectural ethos during the construction of Eastern State Penitentiary in Philadelphia. The goal was to minimize prisoner contact. Guards made liberal use of hoods to prevent inmates from seeing one another, the theory being that the intense solitude would bring reflection, remorse and eventually penitence (the word penitentiary derives from the notion of repentance).

But instead of spiritual peace, it produced widespread insanity. During a visit to the famous Philadelphia prison in 1842, Dickens wrote that each of the inmates was “a man buried alive … dead to everything but torturing anxieties and horrible despair.”

Toward the latter half of the 19th century, enthusiasm for solitary confinement flagged in the face of these crippling effects, only to re-emerge a century later as a way of calming increasingly violent North American prisons.

In 1999, Carleton University PhD student Ivan Zinger noted that, in Canada, the percentage of federal offenders in solitary had doubled over the previous decade to 5.5 per cent of all male inmates. Inmates can, indeed, request a segregation cell, but they need to convince staff that they would be targeted among the general population for any of a variety of reasons, including gang affiliation, perversity of crime, and race. Today, these voluntary admissions make up only 18.3 per cent of male solitary prisoners; the remaining 81.7 per cent go to solitary against their will. Once inside, 67 per cent stay fewer than 30 days, while 6.2 per cent remain for 120 days or more, according to numbers supplied by the Office of the Correctional Investigator.

In the U.S., the tide is turning against segregation. Along with its 75-per-cent reduction in the number of solitary inmates since 2007, Mississippi has recently closed an entire segregation unit. Maine has taken similar measures, cutting solitary by 60 per cent.

Even the Federal Bureau of Prisons has slashed solitary admissions by 25 per cent following a withering Senate hearing in 2012. “The notion of segregation is not one that works,” said Joseph Fitzpatrick, prison commissioner for the state of Maine and perhaps the only North American corrections-system head with a background in prison psychology. “It does not change behaviour for the positive. It actually challenges it and tends to change it in a negative direction.”

In Canada, the Correctional Service seems reluctant to engage in a similar shift, and refuses to discuss that reluctance. During the reporting of this article, the Service refused interview requests, providing only boilerplate statements. “Canadian law and correctional policy allows for the use of administrative segregation in limited circumstances, when there is no reasonable alternative and for the shortest period of time necessary,” spokeswoman Sara Parkes wrote in an e-mail.

Some critics have pressed the Service to ban the practice altogether, something even Dr. Fitzpatrick, the progressive Maine corrections head, says is unrealistic, “I’d love to say we should have zero in solitary,” he says. “But there are individuals who are extremely dangerous, extremely violent. There is a percentage who will maintain a level of dangerousness that will not be respected. Given an opportunity, they will kill if allowed out.”

At first, Mr. Snowshoe expressed satisfaction with his new solitary digs. Over the first few weeks of March, he told his parole officer of his exasperation with strip searches, but he denied any suicidal intent. But by April 13, six weeks in, his story had changed. He wrote a letter to his parole officer praising her for convincing him to “open up” to her, but stating “the change from the Supportive Living Range, to Unit 3, to [solitary] was not what I had in mind … I’m not doing good but I’m not doing bad.”

At the same time, prison officials upgraded him to maximum-security status for the juice-box incident – the judge in the Alberta inquiry would later ask, “How does a juice-box knife end up with 162 days in segregation?” – and were preparing to transfer him to a more secure facility. Eddie was detached about his new status, telling his parole officer, “It’s got to be what it’s got to be.”

He started spending all his time watching television, one of the few amenities – along with music players and books – provided to well-behaved solitary inmates, and often refused his one hour of daily recreation time. He was taking classes in prison, earning several encouraging comments from a math teacher named Karen: “April 26/10 Edward, You keep getting better and better!” But in early June he stopped attending class, citing a lack of motivation.

Within a month, he was discharged from Stony and driven across the Prairies to his new maximum-security home, Edmonton Institution, the same one where James Wigmore had languished. For a young man who had always struggled with change, the move was especially jarring.

Built in 1978, Edmonton Institution is a classic high-security prison: twin four-metre-high razor-wire fences; a constant soundtrack of slamming doors; open hostility between inmates and guards; tense relations between unionized guards and their managers. The segregation cells have a single, glazed window for natural light, each one measuring about five inches across to prevent escapes. In the words of one former employee, “It smelled like the gorilla house at the zoo.”

Mr. Snowshoe’s incarceration was about to spiral downward, with the Correctional Service repeating some of the same mistakes that had led to the death of Ashley Smith three years earlier.

Ms. Smith died on Oct. 1931, 2007, at age 19, after spending much of her teens in federal custody. In a 2008 report, Correctional investigator Mr. Sapers found that Ms. Smith had been disruptive and maladaptive behind bars, triggering over 150 security incidents.

But it was the Correctional Service’s reaction to her behaviour that proved more shocking: In less than a year, she was transferred 17 times between three penitentiaries, two treatment facilities, two hospitals and one provincial jail because of issues involving cell availability, incompatibility with other inmates and staff fatigue.

With each transfer, her “segregation clock” was reset to zero, leaving guards with no way of knowing how long she had spent in solitary, where her health had been declining precipitously.

The constant transfers interrupted any serious course of treatment, and front-line staff lacked the training to deal with mental-health needs. “With misinformed and poorly communicated decisions as a backdrop, Ms. Smith died,” Mr. Sapers wrote, “wearing nothing but a suicide smock, lying on the floor of her segregation cell, with a ligature tied tightly around her neck – under the direct observation of several correctional staff.”

A coroner’s inquiry into the Smith death, completed in 2013, called for a complete overhaul of policy governing solitary placements, one that would be more in line with UN guidelines. Among 104 recommendations, the coroner proposed abolishing indefinite solitary-confinement terms and replacing them with 15-day limits on solitary stays. Annual caps would be set at 60 days, and reviews of segregated inmates would take place at 10-day intervals rather than the current 30-day standard. The government has yet to come up with a response, though corrections officials have told Mr. Sapers that one is forthcoming.

Three years after Ms. Smith’s death, the same banal combination of botched paperwork and poor communication would conspire against Mr. Snowshoe.

Staff at Stony Mountain were well-versed in his adjustment problems, yet their concerns were never passed along to Edmonton, according to two separate investigations conducted into his death. Nor did Alberta staff realize he had spent 134 straight days in segregation before arriving in Edmonton.

Despite the ombudsman identifying segregation-clock resets as a key issue in the death of Ms. Smith two years earlier, the problem remained. As soon as Mr. Snowshoe was released from Stony, his segregation clock returned to zero.

The only thing that staff in Edmonton really knew about Eddie is that he’d been involved in a “security incident” – the juice-box episode – involving threats to officers. In their eyes, it was enough to prove he “jeopardizes the security of the institution or the safety of an individual,” according to one of the commissioner’s directives that govern federal prison conduct. They placed him on handcuff status and locked him away in the hole.

The harsh treatment set him on edge. On July 16, he submitted a written request for transfer from segregation into the general population. A correctional officer signed the request and sent it up the chain to the deputy in charge of inmate placements. And then it vanished. Inmate requests are normally handled within 15 days. This request only turned up in November, 2010, among a stack of documents unrelated to Mr. Snowshoe. By then, he had been dead for three months.

That same day, July 16, Mr. Snowshoe asked to speak with a psychiatrist about altering his medication. And during a health assessment with a nurse, he disclosed his suicide and self-harm attempts, which were faxed to the psychology department for followup. The red flags failed to trigger any special attention. There was a Mental Health Committee to develop intervention plans for troubled inmates, but the committee didn’t accept referrals from the Segregation Unit.

It was a baffling omission, given that one mental-health worker at the prison told the Board of Investigation that “approximately 50 per cent of the inmates in the Segregation Unit had mental-health needs.” One recent Correctional ombudsman study revealed that 47 per cent of federal prison suicides from April, 2011, to March, 2014, happened in solitary conditions.

For Mr. Snowshoe, there would be no followup. The parole officer assigned to him never bothered to meet Mr. Snowshoe during his time in Edmonton – because of conflicts with his summer holidays, according to the provincial fatality review conducted this year.

After an inmate’s first five days in segregation – and at 30-day increments from then on – a review board is legally bound to meet with the prisoner to assess his well-being and suitability for return to another unit.

On July 23, Mr. Snowshoe refused to attend his five-day review. In his absence, the board recommended he remain in segregation. On Aug. 13, it was time for his 30-day review; again, Mr. Snowshoe refused to go, and again, the board interpreted his recalcitrance as a sign he should remain in solitary.

On that same August day, Effie Bella decided she would write a letter to her eldest son. Her repeated attempts to reach him by phone had been largely unsuccessful. She churned it out in a tidy longhand, accompanied with pages from the Sears catalogue. She instructed Mr. Snowshoe to circle the clothes he wanted to wear upon his release. She had a bad feeling, as she would explain in the letter, which she wrote on Friday but decided she would send on the following Monday:

I have a feeling we’re never gonna see you again so anyways I gotta go. Take care remember I will always love you lots.

Love from your Mom Effie Bella Snowshoe

Friday was bingo night in Fort McPherson. On that August evening in 2010, Effie Bella Snowshoe had her radio tuned to the moccasin telegraph to hear the numbers called over the air. As she filled her card, she could hear a commotion out front of her house that sounded like a fight. “What’s that noise?” she said to one of her younger sons, Herbie, who was washing dishes in the kitchen.

“Crows,” he replied.

She saw a dozen or so ravens – which she called crows – strutting and cawing in the front yard. A chill went up her spine. “When you get a mess of crows like that, that’s bad luck,” she said. “They’re trying to tell me something.”

Like many in Fort McPherson, Ms. Snowshoe is sensitive to omens and superstitions. Even in private, she never talks ill of bears, lest they hear her and decide to trash her house. She grips Blue Jays memorabilia whenever her favourite baseball team is on television. And even now she plays a sentimental Vince Gill song – Go Rest High on That Mountain – every morning as a kind of prayer for Mr. Snowshoe.

In local culture, only one thing was a surer sign of bad luck than so many black birds: success at bingo. There is a certain logic behind bingo’s ominous reputation. With the game broadcast far and wide, everyone instantly knows the identity of the jackpot winner. No sooner would the winner be announced than every hard-up boozer and reprobate in town would start showing up on that person’s doorstep asking for money.

Effie looked at her card. She still needed five numbers to win. Only an improbable streak would net her the jackpot. Then, one after another, her numbers started coming up. She hit three in a row, then four. One more would get her $300 and almost certain misfortune. “When you got the crows and you win bingo, that’s not good,” she said.

The omens began messing with her head. Mr. Snowshoe hadn’t called in weeks. She had phoned his parole officer five times over the previous 20 days, but nobody called her back. She was worried, but assumed all was fine. His release was scheduled for Boxing Day, and what better Christmas present could there be than reuniting with her Eddie?

She hit on the fifth number. She rushed out to collect her winnings and went to a friend’s house to hide for the evening. That’s where two Mounties found her.

“Do you have a son named Edward Snowshoe?” she remembers them asking her at the doorstep.

“Yes,” she said.

“We’re sorry to inform you your son has passed away.”

Her legs gave out. She woke up on her couch, not knowing how she got there.

Back at Edmonton Institution, some staff members were in shock. “After something like this, everyone always asks how it happened,” says Teresa Kellendonk, a former chaplain at the facility. “He was on a forward plan, he was talking optimistically. He was talking future-oriented. You get news like this and we would ask ourselves what didn’t we ask, what didn’t we see.”

It was all familiar. One year earlier, another young aboriginal man, Raymond Yellowknee, had taken his life in the prison’s segregation unit. A followup fatality report issued by an Alberta judge urged the prison to better share information about inmates presenting suicide concerns and to prohibit the “practice of placing mentally ill offenders at risk of suicide or serious self-injury in prolonged segregation.”

Everyone from the ombudsman to the John Howard Society has been peppering the Correctional Service with similar urgent recommendations for years. And, in its slow, bureaucratic way, the agency has progressed somewhat. In recent years, the service has instituted a mental-health strategy, and improved training for front-line staff. Mental-health spending has increased, but still constitutes only about 2.5 per cent of the agency’s annual $2.7-billion budget.

Ms. Snowshoe spent three-and-a-half years dealing with the grief. It was starting to ease somewhat when Alberta fulfilled its legal obligation to hold a fatality inquiry into Eddie’s death earlier this year – the delay is typical of an overburdened system. She flew to Edmonton for the testimony. Like so many grieving families before her, she heard how the Correctional Service failed to save her son from a fate he had been telegraphing for years.

The resulting report, written by Justice James K. Wheatley, lacerated the Correctional Service on several fronts, concluding that “Edward Christopher Snowshoe fell through the cracks of a system …” The Service was virtually mute after the report came out, telling reporters it would need ample time to read the five-page document before responding. Such a delay tactic is familiar to Mr. Sapers, the ombudsman.

He is still awaiting a satisfying response to the recommendations he made after Ms. Smith’s death. And the Service is still preparing a public rebuttal to the 104 coroner’s recommendations released last year in the Smith inquiry.

“While I appreciate that the inquest covered a number of similar issues of concern and made several recommendations consistent with my Office’s own investigation and follow-up to Ashley Smith’s death, the delay in response is increasingly untenable and unacceptable,” Mr. Sapers stated in his most recent annual report. “It is now nearly seven years since Ashley’s death in October 2007. … Suffice to say, there remains considerable work to be done in terms of improving the operations and accountability of the federal correctional system to safely house, treat and manage the most profoundly mentally disordered offenders. This work should not be further delayed.”

Every time Ms. Snowshoe closes her eyes at night, she says she sees Eddie in a dark room. She had been told she should seek justice or money or both. The one thing she seeks, she can’t have: “I want him back.”

Her intense grief has become a matter of local concern. Elders have told her that Mr. Snowshoe will remain in a kind of purgatory until her mourning ends. “When you cry, you keep them wandering around,” she says. “They are not in heaven. They are just wandering around up there. So one day, I’ll let him go.”

On that day, she plans to burn all the remnants of her son’s time in prison, especially a canvas bag she carries everywhere containing Edde's suicide note and death certificate. Until she can face those cathartic flames, she will continue to visit his grave every few days and say a prayer before a cross that reads, “We love you my boy, till we meet again.”