Ursula Eriksson stands next to her twin sister Sabina on the side of the M6 with her hands in the pockets of her lime green coat on a wet spring day.

A traffic officer talks to them with his colleagues grouped nearby, the flashing lights of their marked patrol car seen ahead on the hard shoulder as cars whizz past.

Officers have been called to the scene after the Swedish siblings were captured on CCTV running into oncoming traffic in an apparent suicide pact mission.

Seconds later, Ursula dumps her bag and makes a bolt for it. Her cap plummets to the ground as an officer desperately attempts to grab hold of her.

She wriggles free from her jacket and steps in front of a lorry, her legs crushed by the impact.

Sabina follows her sibling and is hit by a Volkswagen Polo. Distressing footage shows them both lying motionless in the middle of the motorway, with officers fearing they are dead.

But they miraculously survive. Sabina is unconscious for fifteen minutes before she springs to life and punches a female officer in the face in what an eyewitness describes as a show of ‘superhuman strength’.

Ursula, meanwhile, struggles with cops as they come to her aid and screams, ‘I’m going to f***ing haunt you. B***h a**. I’m gonna haunt you.’

The case of the ‘twisted twins’ in 2008 is one of the most chilling and bizarre incidents to have ever been captured on camera in Britain, and it sparked a chain of events that led to the brutal killing of a former RAF airman.

It left police baffled, with psychologists believing it was caused by a rare psychological phenomenon called ‘folie a deux’ – or the madness of two.

Now, a two-part Channel 5 documentary, Twisted Sisters: Madness and Manslaughter will try to unravel what led to the sequence of tragic events that ended with the stabbing of kind-hearted Glenn Hollinshead.

In May 2008, the Eriksson sisters arrived in the northwest of England after secretly fleeing from mother-of-two Sabina’s marital home in Ireland.

The identical twins boarded a National Express bus from Liverpool to London. At Keele services, the driver made an unscheduled stop after Ursula and Sabina started behaving erratically.

Police were called to the service station, but cops allowed them to leave.

From there, they made their way on foot to the busy M6 where traffic officers were being filmed for the BBC series Motorway Cops, which captured the horrifying scenes that followed.

Cameraman David Rea said: ‘In all my career I had never filmed anything like this before. And either before or after.’

As officers came to the twins’ aid and wrapped them in foil blankets, Ursula was heard saying to one cop: ‘I recognise you, I know you’re not real.’

She then added: ‘You’re going to steal my f***ing organs, you bitch.’

Emergency doctor Dr Latif Hussain would come into contact with Sabina three times. He was one of the first medics to arrive at the scene and said that, with the speed the HGV was travelling at, he would have expected a fatality.

‘I was very surprised that she (Ursula) was actually conscious,’ he said. ‘Under the circumstances, I found it really quite bizarre that this individual had certainly got limb-threatening, potentially life-threatening injuries.

‘But she was very agitated, kicking, screaming, shouting.’

Meanwhile, Sabina remained motionless nearby on the floor. Eyewitness Richard Cussons, who later would help restrain her, said he thought she was dead.

Much to his shock, Sabina stood up, punched an officer to the floor, and ran across the carriageway. She was arrested on the roadside and screamed ‘snuff movie, huh’ repeatedly.

‘To me, that wasn’t really human,’ Mr Cussons said. ‘You don’t get run over by a car doing, 60, 70 on the motorway, then by another car, thrown into the air, falling unconscious for 10 minutes and then go running over to try and do it again.’

It took six people to restrain Sabina, with a force from one of her kicks reportedly breaking a removal van man’s rib.

‘The overriding impression that I had was that she had superhuman strength,’ Mr Cussons said.

Ursula was sedated and airlifted to Royal Stoke University Hospital, while Sabina, who had been carried off in handcuffs and leg restraints, was taken by ambulance to the same hospital.

Officers initially believed they may have been under the influence of drugs, but tests revealed that neither sibling had taken any substances.

Five hours later, much to the surprise of one medic, Sabina was released from hospital with ‘minor injuries’ while still wearing her hospital gown.

She was taken into custody, where, during the journey, she told officers she was a ‘licensed boxer’.

Sabina was filmed laughing, joking, and flirting with officers and oddly told the custody sergeant she had never tried to harm herself.

She eerily told one officer: ‘They say always in Sweden an accident rarely comes alone. Usually at least one more follows, perhaps two.’

She was held for two nights before being taken to the magistrates’ court and convicted of trespassing on the motorway and assaulting a police officer.

Having already served her one-day sentence, Sabina was allowed to walk free. But with nowhere to go, she aimlessly wandered around the streets of Fenton, in Staffordshire, with her items in a clear plastic bag.

There, she bumped into Glenn Hollinshead, 54, who was walking home from the Royal Oak pub with his dog and pal Peter Malloy.

Speaking in 2010, Peter said: ‘It was time to go home. We started walking up Christchurch Street, and as we were walking up, there was a woman.

‘She stuck out like a sore thumb in the middle of the street, wearing this big bubble jacket with all her stuff in a plastic bag. She seemed a little distressed. Lost. Certainly not very focused.’

Sabina told the pair she was trying to find her sister who was in hospital and needed a bed and breakfast for the night.

Kindhearted Glenn offered to take her back to his house for some food, but whilst there she began acting strangely.

‘In the quiet moments, she was getting quite paranoid and pulling the curtains to one side,’ Malloy said.

‘I responded a little unsettled by this and looking to Glenn for reassurance.’

He added: ‘There was this growing fear inside of me thinking, who is this woman? She’s hiding from someone.

‘She gets out her cigarettes and she offers them round to myself and Glenn. We take one and just as we were about to light up, she just snatches them quite furiously and says, “they might be poisoned, you can’t have them”.

‘I was taken back by that, like, what? Your cigarettes are poisoned? And this was a pack of cigarettes that she’d been smoking from all night.

‘This is beyond weird now, something’s not right about this woman. Glenn was quite relaxed and comfortable with it. I think he was just dismissing it as quirky. I personally just wanted to get out of that situation as quickly and as calmly as possible.’

Malloy left, and Sabina ended up staying the night at Glenn’s home.

In a cruel twist of fate, one of Glenn’s brothers, Peter, was an A&E nursing assistant at the hospital where the Erikssons were taken for treatment.

Glenn had phoned Peter to tell him about Sabina and that her sister had been involved in a crash.

He rang him back to let him know Ursula had been operated on and could offer her a lift to the hospital, but she declined.

‘If I had known about the M6, I could have warned Glenn that what she’s told isn’t what happened,’ he said.

‘I could have warned him that she is very dangerous and to be careful.’

The next morning, Glenn went to a neighbour and asked to borrow some tea bags. But when he got back, Sabina stabbed him three times in the chest and once in the throat with his own kitchen knife.

He staggered back outside and spoke his final words to his neighbour, saying: ‘She stabbed me, she stabbed me. Here, look after my dog.’

Sabina ran from the home with one eyewitness saying he saw her with ‘lots of blood on her head’ after hitting herself with a hammer.

She then smacked a Good Samaritan who had stopped to help her on the back of the head, before running across a roundabout as she was chased by two paramedics.

Sabina then jumped 30ft from a bridge and landed on the A50 below, fracturing her ankle and injuring her head.

Dr Hussain, who had also deemed Sabina fit to be detained in custody, was once again the medic to be called to the scene.

He told of his shock to find it was the same woman he had seen on the motorway and in custody.

While in hospital, Sabina was arrested and charged with Glenn’s murder. Forensic psychiatrist Carol McDaniel was instructed to carry out a report on Sabina for the prosecution.

She said: ‘The defence expert felt Ursula was in fact suffering from a serious mental health issue and that Sabina Eriksson’s behaviour was due to the presence and the influence of her sister.

‘And their diagnosis was folie à deux, a French term, meaning the madness of two.

‘One person would have what we call the primary diagnosis of a true mental illness. And then because of their intimacy, they could convince that other person to think just as they were thinking.

‘It’s almost as if you would consider it being contagious. In the case of the sisters, there was an indication that Ursula was the primary patient.’

Dr McDaniel met and assessed Sabina, and instead believed she was suffering from acute polymorphic psychotic disorder – ‘where the person’s mind simply takes leave of reality’.

She said: ‘Prior to what had happened to Mr Hollinshead, it seemed that she was having persecutory delusions, hearing voices, and thought that she was in danger.

‘And this was made clear to her by Ursula. And that is when she was convinced that they needed to seek refuge.

‘They considered escaping together one way or the other, like a pact. What was said to me by Miss Eriksson was that they were both convinced that they had to act in this way.

‘And that by dying together, that would be one way of escaping whatever perceived danger that they had imagined.’

Dr McDaniel said Sabina was still suffering from a paranoid delusion when she met Glenn.

‘When Mr Hollinshead went out to speak to his neighbour, it is possible that she might have felt they were plotting in some way,’ she said.

Sabina pleaded guilty to manslaughter on the grounds of diminished responsibility and was sentenced to five years in prison, minus the time spent on remand.

Glenn’s brother, Garry, felt the diagnosis of folie a deux was ‘very convenient’.

‘I don’t believe there is any woo-woo type mysticism where one girl is transferring her thoughts to another girl, even though twins are very close,’ he said.

He firmly believes Glenn would still be alive if Sabina had been sectioned under the Mental Health Act after the M6 incident.

But Dr McDaniel said her intermittent signs of psychosis meant ‘things slipped through the net’.

A spokesman for Staffordshire Police said: ‘Whilst in custody, Sabina had a mental health assessment under Section 136 of the Mental Health Act and was seen by a psychiatric consultant, a doctor and an approved social worker. They did not section Sabina or consider that she required this.’

Sabina is believed to have returned to her native Sweden, while Ursula is reported to be ‘part of a close-knit Christian community’ in America. Neither have reportedly had any further mental health episodes.

[H/T Daily Mail]