To the outside world, Marc Rieben and Kristina Joksimovic lived a charmed life, often described by friends as the 'perfect family'.

She was a former Miss Switzerland finalist and a catwalk coach. He was the son of a successful lawyer, with a good job, a large home and a reputation as a devoted father.

Photos uploaded by Kristina to social media showed the couple smiling alongside their two young daughters, in carefully curated posts that masked a far darker reality.

Just four weeks before she was killed, Kristina shared images from a 'couple's getaway', the snowy landscape visible from a luxury hotel above Lake Lucerne.

From the outside, it was a picture of success and stability - but then the unthinkable happened.

In February 2024, Rieben killed his wife in a violent rage before dismembering her body and putting body parts in a blender - 'pureeing' them, as the autopsy described it.

The horrific nature of what happened sent shockwaves far beyond Switzerland.

The couple, who married in 2017, lived in a spacious semi-detached home overlooking the affluent hills of Binningen, near Basel. 

To neighbours and acquaintances, Rieben appeared the model husband. He was a devoted father and volunteered with a scout group in his free time.

Former Miss Switzerland Nadine Vinzens, a friend of Kristina, told Nau.ch: 'She always made a happy impression on me. I would never have thought that her husband would do something like that.'

'To me, they seemed like the perfect family,' another one of Kristina's friends told local outlet Blick at the time.

As Rieben's trial is set to begin on Monday, prosecutors say the motive behind the killing has come into focus for the first time, Swiss paper Tages-Anzeiger reported.

According to an indictment filed by the Baselland Public Prosecutor's Office, the violence ensued during an argument over the couple's separation. 

On February 13, the pair are said to have discussed the terms of an impending split over lunch.

Rieben allegedly refused to accept the divorce, wanted full-time custody of the children, and denied financial support to his wife, the paper reported. 

What followed was the fatal escalation, far removed from the arguments they were known to have had during their marriage.

During the altercation, prosecutors say Rieben grabbed his wife by the throat and pressed her against the wall.

He then reportedly wrapped a 'ribbon-like object' around her neck and strangled her, before mutilating and pureeing her body.

The full details of what happened on that tragic day in February are laid out in harrowing detail in court documents obtained by the Daily Mail.

An autopsy found that Kristina's body showed signs of blunt force trauma, including cuts to her face and bruising to her leg, foot, shoulder blades and the back of her head. Some of her hair had been torn out.

After her death, Rieben dismembered her body using a jigsaw, a knife and garden shears. 

Investigators say he 'carefully removed' her womb, the only organ taken from her torso, in what experts described as a 'deliberate mutilation or ritualised degradation of the body' that may indicate a mental disorder.

Some body parts were placed into an industrial blender, while others were dissolved in a chemical solution. 

Investigators also found that he played YouTube videos on his phone while carrying out the dismemberment.

Inside the basement laundry room of the family home, described as an 'isolated bunker with thick concrete walls', investigators later discovered 'a large number' of skin flaps, 'some with attached muscles', along with pieces of muscle and bone.

The grim discovery of Kristina's dismembered body was first made not by police, but by her father.

After she failed to collect her daughters from kindergarten, her parents grew concerned. 

When her father went to the house, Rieben reportedly claimed he did not know where she was. 

For hours, he behaved as though nothing was wrong, cooking dinner and talking with his father-in-law before putting the children to bed.

'Rieben kept insisting he didn't know where Kristina was and claimed she would just leave sometimes,' a friend told the Daily Mail.

While Rieben spoke with Kristina's mother on the phone, her father searched the house room by room. 

In the basement, he noticed a black bin bag with strands of blonde hair protruding.

'When he opened the black bin bag, he saw her cut off head with the hair still attached,' the family friend said.

He ran outside screaming, urging a passerby to call the police, before returning to confront his son-in-law.

According to reports, Rieben, who did not expect the body to be found so soon, showed complete indifference and a lack of emotion upon his arrest.

Rieben later admitted to dismembering his wife, citing 'self defence' and claiming he dismembered her 'in a panic'.

Describing what happened before the killing, Rieben said that the couple had a 'positive' conversation before Kristina 'suddenly attacked him with a knife'.

Although Kristina's family have not made a public statement, local media has reported that her parents both received intensive psychiatric support following the discovery of their daughter's dead body.

In the wake of the incident, testimonies from friends emerged, detailing a starkly different private reality marked by violence and abuse prior to her killing.

One of Kristina's closest friends alleged that Rieben was controlling and increasingly withdrawn. 

'She was really in love at the beginning, but I was a bit surprised when she got into a relationship with him as he didn't suit her at all. He came across as really introverted, very critical and sometimes quite arrogant,' she told the Daily Mail.

'He was really derogatory with her, with gestures, words and even his tone… he wanted Kristina to disappear.'

She added that the relationship had deteriorated after the birth of their children.

'Kristina often told me that their relationship, especially since their children were born, was going badly.

'He turned in on himself more and didn't let anyone get close. She tried to talk to him and to save the relationship. They attended couple's counselling together, where he always left or refused to attend. She didn't really know what to do as it got worse.

'She told me that she had to [call the] police once, but wouldn't tell me details about this, only that he was violent and threatened her that if she called the police, he would turn it around on her and she would see what would happen to her then.'

A long-time friend of Kristina described Rieben as increasingly obsessive, particularly when it came to their children. 

'They were his perfect project and Kristina was in the way,' she said.

She added that he controlled many aspects of their upbringing, from strict bedtimes to banning screen time and limiting what they could listen to. 

He reportedly insisted they avoid 'feminine clothing' and placed importance on them growing up multilingual.

'He hates femininity,' she added, referring to the removal of Kristina's womb.

Prosecutors say Rieben had a history of violence, and had in the past choked his wife, which investigators were able to prove based on older photos of the victim. 

Other allegations include that he had previously grabbed a former partner by the neck, hit her and pushed her against a wall.

According to the indictment, Rieben committed the murder in a deliberate and intentional manner, with full awareness, and out of 'a selfish attitude and mindset characterized by a need for control, hurt feelings, revenge, and intense rage'.

The 42-year-old was diagnosed with narcissistic and obsessive compulsive traits by a forensic psychologist, who described him as a 'highly rational thinker with a pronounced cognitive-technical perspective'.

Investigators said Rieben showed a 'lack of empathy and cold-bloodedness after killing his wife' and displayed 'sadistic-sociopathic traits'.

His risk characteristics were found to include 'increased rigidity,' a heightened need for control, egocentricity, anger-driven reactivity, and a tendency toward manipulation.

The psychiatrist disputed the self-defence claim, arguing that victims of sudden, life-threatening attacks usually contact the police right away to report the trauma without hesitation or 'filtering' the details. 

In addition, the expert said that his behaviour after the incident consisted of a series of 'prompt, purposeful, and methodically executed actions', which contradicts Rieben's claim of 'panic'.

His actions only make psychological sense if his interest lay in 'eliminating as many traces as possible, including the body, in order to conceal what actually happened,' added the expert in comments reported by Tages-Anzeiger.

Rieben's trial will begin on May 4 at the Basel-Landschaft Criminal Court in Muttenz and is scheduled to last five and a half days. The verdict is expected on May 13.