What is the point of sending someone to prison - retribution or rehabilitation?
Twenty years ago, Norway moved away from a punitive "lock-up" approach and sharply cut reoffending rates.
The BBC's Emma Jane Kirby went to see the system in action, and to meet prison officers trained to serve as mentors and role models for prisoners.
"OK, and now put your big toes together and put your bum behind you!" calls the enthusiastic yoga instructor in English to the 20 or so participants who are shuffling into child's pose on rubber mats spread out on the grass in the faint early morning sunshine.
"Can you feel the stretch?" she gently asks a heavily tattooed man as she settles his ruffled T-shirt and smoothes his wide back with her hand. "It's OK, yeah?"
It could be a yoga class at any holistic health retreat anywhere in the world but the participants here at Norway's maximum security Halden Prison are rather far removed from the usual yummy mummy spa clientele. Barefoot murderers, rapists and drug smugglers practise downward-facing dog and the lotus position alongside their prison officers, each participant fully concentrating on the clear instructions from the teacher.
"It calms them," says prison governor Are Hoidal approvingly, as we watch from the sidelines. "We don't want anger and violence in this place. We want calm and peaceful inmates."
Tranquillity does not come cheaply. A place at Halden Prison costs about £98,000 per year. The average annual cost of a prison place in England in Wales is now about £40,000, or £59,000 in a Category A prison.
A uniformed prison officer on a silver micro-scooter greets us cheerily as he wheels past. Two prisoners jogging dutifully by his side, keep pace.
Hoidal laughs at my nonplussed face.
"It's called dynamic security!" he grins. "Guards and prisoners are together in activities all the time. They eat together, play volleyball together, do leisure activities together and that allows us to really interact with prisoners, to talk to them and to motivate them."
When Are Hoidal first began his career in the Norwegian Correctional service in the early 1980s, the prison experience here was altogether different.
"It was completely hard," he remembers. "It was a masculine, macho culture with a focus on guarding and security. And the recidivism rate was around 60-70%, like in the US."
But in the early 1990s, the ethos of the Norwegian Correctional Service underwent a rigorous series of reforms to focus less on what Hoidal terms "revenge" and much more on rehabilitation. Prisoners, who had previously spent most of their day locked up, were offered daily training and educational programmes and the role of the prison guards was completely overhauled.
"Not 'guards'," admonishes Hoidal gently, when I use the term. "We are prison 'officers' and of course we make sure an inmate serves his sentence but we also help that person become a better person. We are role models, coaches and mentors. And since our big reforms, recidivism in Norway has fallen to only 20pc after two years and about 25pc after five years. So this works!"
In the UK, the recidivism rate is almost 50pc after just one year.
The architecture of Halden Prison has been designed to minimise residents' sense of incarceration, to ease psychological stress and to put them in harmony with the surrounding nature - in fact the prison, which cost £138m to build, has won several design awards for its minimalist chic. Set in beautiful blueberry woods and peppered with majestic silver birch and pine trees, the two-storey accommodation blocks and wooden chalet-style buildings give the place an air of a trendy university campus rather than a jail.
A thick, curving 24ft-high concrete wall snakes around the circumference of the prison but there's no barbed wire or electric fence in sight and you really have to look for the discreet security cameras. There are movement detector sensors on each side of the wall, Hoidal assures me - but no-one has ever tried to escape.
When I see the inside of a cell - every inmate has his own cell, which comes with an en suite toilet and shower room, a fridge, desk, flat TV screen and forest views - and when I clock the immaculate sofas and well-equipped kitchenette in the communal common room, I ask Halden's governor whether the level of comfort here isn't a bit too cushy.
Are Hoidal nods politely. He's been expecting this question, of course. It's one he answers every day, whether it comes from astounded foreign journalists or from critics within Norway itself.
"It is not easy to have your freedom taken away," he insists.
"In Norway, the punishment is just to take away someone's liberty. The other rights stay. Prisoners can vote, they can have access to school, to health care; they have the same rights as any Norwegian citizen. Because inmates are human beings. They have done wrong, they must be punished, but they are still human beings."
In the on-site garage, two inmates in overalls are tinkering with the wheel arch of a car, brushing out mud and carefully re-fixing bolts. Like most of the prisoners here, they leave their cells at 07:30 each morning and are at work by 08:15. Apart from one hour's rest in their cells during the afternoon, to coincide with the guards' break, they are not locked in again until 20:30 at night.
The idea is to give them a sense of normality and to help them focus on preparing for a new life when they get out. Many inmates will be released from Halden as fully qualified mechanics, carpenters and chefs.
"We start planning their release on the first day they arrive," explains Hoidal, as we walk through to the carpentry workshop where several inmates are making wooden summer houses and benches to furnish a new prison being built in the south of Norway.
"In Norway, all will be released - there are no life sentences," he reminds me.
"So we are releasing your neighbour," he continues. "If we treat inmates like animals in prison, then we will release animals on to your street."
(The maximum sentence in Norway is 21 years, but the law does allow for preventative detention, which is the extension of a sentence in five-year increments if the convicted person is deemed to be a continued threat to society.)
In the graphic design studio, quietly spoken Fredrik is putting the finishing touches to his striking design for the front cover of the prison's cookery book. Sentenced to 15 years for murder, Fredrik says he has struggled to come to terms with what he has done and the pain he has caused. Going on a silent three-week retreat within the prison has helped him achieve peace, he adds, and to reflect on his past.
He is not boasting when he tells me that he's achieved a diploma in graphic design since he arrived at Halden, nor that he's passed eight other exams at A and B grade and is now studying the Norwegian equivalent of A-level maths and physics; he is just keen that I should understand he is using his time inside wisely for a projected future outside the curved wall.
"If you don't have opportunities and you are just locked in a cage, you don't become a good citizen," Fredrik says as he adjusts the colours on one of the photos on his screen. "Here there are good opportunities, you can have a diploma and when you come out, you can maybe get a stable job and that's important."
When I congratulate Fredrik on his recent exam success he nods shyly and confides that he hopes, once he's transferred to an open prison, to work on getting a degree, a Masters, or even a doctorate.
Normalising life behind bars (not that there are any bars on the windows at Halden) is the key philosophy that underpins the Norwegian Correctional service. At Halden, this means not only providing daily routines but ensuring family contact is maintained too. Once every three months, inmates with children can apply to a "Daddy In Prison" scheme which, if they pass the necessary safeguarding tests, means they can spend a couple of nights with their partner, sons and daughters in a cosy chalet within the prison grounds.
"Lots of toys and children's books," points out prison officer Linn Andreassen as she unlocks the gate and shows me the little play garden. I note the double bed in the main bedroom, flanked by a cot.
"Yeah, they get to play house, play happy families," she smiles. "It's a big privilege for them so they have to earn it."
Linn is a slight young woman in her early 30s. She's been in the prison service for 11 years already, 10 of which have been spent at Halden - almost half of the staff at this category A prison are female. But Linn assures me she has sounded a personal alarm that all Norwegian prison officers carry only twice in her career, and insists she has never felt sexually threatened.
"It's normal to have women in society," she shrugs. "So the guys here need to cope with that. They need to respect not just the uniform but the person, the woman as well. And we respect them, so they respect us."
In the craft workshop, John, who is serving a long sentence for drug smuggling, is stitching a black toy sheep on his sewing machine. When I ask John what is good about the Halden regime, the presence of female officers is one of the first things he mentions.
"They're more effective to keep the macho guys down," he reflects thoughtfully. "You have to think a bit differently around them." He places an eye on to his sheep, ready to stitch.
"And when we play football, women are not such bad referees."
Another prisoner, Khan, is interested in our conversation and puts down the frog he's sewing.
"We are lucky to have women in the guard system," he agrees. "It normalises things."
It takes 12 weeks in the UK to train a prison officer. In Norway it takes two to three years. Eight kilometres north-east of Oslo in Lillestrom, an impressive white and glass building houses the University College of the Norwegian Correctional Service, where each year, 175 trainees, selected from over 1,200 applicants, start their studies to become a prison officer.
Hans-Jorgen Brucker walks me around the training prison on campus, which is kitted out with reproduction cells and prison-style furniture. I note a bulging pile of helmets and stab vests in one storage room. Brucker acknowledges that prison officers will undergo security and riot training, but he's fairly dismissive of this part of the course.
"We want to stop reoffending which means officers need to be well educated," he says. He shows me a paper outlining the rigorous selection process, which involves written exams in Norwegian and English (about a third of the prison population is non-native, so officers are expected to be fluent in English) and physical fitness tests.
"My students will study law, ethics, criminology, English, reintegration and social work. Then they will have a year training in a prison and then they will come back to take their final exams."
He winces when I ask him if he would employ a prison officer who had trained for only three months.
"I think there is a high risk for corruption with a short training," he says, clearly a little uncomfortable criticising the UK's system.
"In our system, officers are quite well paid and when an officer knows more about the law, he knows more about how to deal with inmates and how to avoid violence."
Every year his students go to the UK to spend a day observing an English prison and I ask him what his students say about their experience in English high-security jails. He tells me they are always surprised by the noise, the crowding and the relatively small number of staff.
"It's an eye-opener," he says, clearing his throat politely.
The only loud noise at Halden that I encounter comes from the TV in the drug addiction unit's sitting room, where a rather spaced-out looking inmate is watching a cops and robbers show. At one point my guide, prison officer Linn Andreassen, disappears briefly to check something with a colleague and I am left alone with the inmate. He grins at me, points to the gun-wielding policemen on screen and makes a joke in Norwegian before wandering off to his cell.
When I ask the prison governor, Are Hoidal, about the level of violence in Halden prison, he looks genuinely surprised. I tell him that in England and Wales, assaults on staff have almost tripled in five years and that there were 10,213 assaults on staff in 2018, with 995 of those classed as serious.
He scratches his head.
"Of course, in some of our older prisons there is occasional violence but I really don't remember the last time we had violence here," he reflects. "Maybe we had one or two incidences of spitting?"
In the gardens at Halden, 28-year-old trainee officer Jon Fredrik Andorsen is taking a break from his duties with his experienced colleague, Linn. At Halden there are 258 inmates (including 22 who are in a half-way house on the other side of the wall) and 290 employees, 190 of whom are prison officers. (The rest work as workshop tutors, teachers and admin staff.) Jon Fredrik, who used to work as a car salesman, admits he would never have considered joining the prison service if he hadn't felt his safety was guaranteed. So far, he says, he has never felt threatened at Halden - he has confidence in his training and in the wisdom of the more experienced officers. Norwegian prison officers do not even carry pepper sprays.
"My first defence is my voice and our social connection with the inmates," he explains. "We defuse situations before they happen."
Linn interjects: "You can't help others if you don't have good conditions yourself. You need to have a clear head at all times in this job. To focus. If you're going around scared you can't help anyone."
She tells me how shocked she was, when visiting a prison in the UK, that prison officers told her it was dangerous to stand in certain places around the building as the inmates might throw things down on her. She screws up her face.
"And there were so many prisoners! The UK locks up a lot more people than here in Norway, no?"
Scotland, England and Wales have the highest imprisonment rates in Western Europe. Scotland locks up 150 people per 100,000 of the population and England and Wales almost 140 people, compared to Norway's 63.
The smaller prison population means that at Halden prison, for instance, each officer can be given three individual prisoners for whom he or she will act as a point of contact. The contact officer helps fill out applications, addresses complaints and makes sure that inmates get their quota of phone calls home.
Kim, who is serving 17 years for murder, raises his eyebrows rather sarcastically when I mention this system.
"Some prisoners like to interact and some don't," he shrugs, closely watching Are Hoidal, who is in the room with us.
"I'm sceptical about opening up to guards too much - if I open up will they use it against me? It's a double-edged sword. Some guards are OK but…" He trails off, still looking at Hoidal who is grinning good-naturedly back at him.
As Hoidal and I walk back together towards his office, past some colourful abstract paintings, he reminds me that the practice of dynamic security at Halden is not always popular with prisoners because the officers' omnipresence makes dealing drugs difficult. There certainly is drug dealing at Halden, he admits, but these are not drugs like heroin and spice that have been smuggled into the prison from outside, they tend to be medications - opiates and painkillers - that inmates have been prescribed by prison doctors.
Hoidal is extremely enthusiastic about the prison's new projects. A choir has just started up - inmates already have their own on-site recording studio, the aptly named Criminal Records - and he's hoping for a Christmas concert to coincide with the release of the inmates' new cookery book. But underneath his indefatigable positivity there is a nagging worry; profits from oil production in the North Sea are dwindling and the government has warned that swingeing cuts - including to prison budgets - are on their way.
"If you want quality and high-class results, we need money," argues Hoidal firmly. "I fear there will be more violence and the recidivism rate will go up if we can't have all the programmes we have now. It's not good. It's not good at all."
In Unit C, a cell door has swung open and I can see a red rose in a glass on the window sill. The former occupant has just been transferred to another lower-security prison but, perhaps needing to impart the wisdom he has learnt during his time at Halden, he has stuck a hastily scrawled message on the magnetic whiteboard for the new inmate who will take his place.
"To love is to give without asking for anything back," his note reads. "Loving makes you free. Free from yourself, my friend." (UNI)