Reporter: Michael Usher
Producers: Stephen Taylor and Jim Nally
This story would have to get our vote as the strangest of the year.
In fact, it's so weird, if it wasn't for the cameras, you'd be hard pressed to believe any of it even happened.
But, tragically, this is a real story. It began when forty-year-old identical twins from Sweden wandered out onto one of Britain's busiest motorways.
That single moment of madness triggered a sequence of events that ended in murder.
Full transcript:
STORY -
MICHAEL USHER: The M6 is one of England's busiest motorways - thousands of cars, buses and trucks use it every hour. But, in May 2008, a day like no other. CCTV cameras reveal something highly unusual - two women walking right down the middle of the six-lane highway. But, then, it becomes incredibly dangerous - they suddenly jump the rails and run into the traffic. Police officers Tracey Cope and Paul Finlayson race to the scene, and with them is a BBC cameraman working on the reality show 'Motorway Cops', seen on Foxtel's Crime and Investigation network. Over the police radio the officers are told one of the women has been struck by traffic but, when they arrive, they're surprised.
PAUL FINLAYSON, POLICE CONSTABLE: Looking back on it, things didn't seem completely right. We were expecting a casualty on the road and obviously we've now got two people standing there.
MICHAEL USHER: The women are 40-year-old identical twins from Sweden, Ursula and Sabina Erikkson, and, at this point, they're seemingly calm and uninjured. As one highway worker stays with the sisters, his colleague tries to tell the police what's happened, but then all hell breaks loose. For the second time, Ursula intentionally runs out into the oncoming traffic, and is run over by a truck. Then, her sister Sabina also makes a break for it, running onto the busy motorway, and she is hit by a car.
PC PAUL FINLAYSON: Seeing her body thrown so violently, seeing her actually run over by the wheels of the trailer itself, I was convinced that no human body was going to survive that.
PC TRACEY COPE: I then saw the silver vehicle make direct contact with the other sister and literally throw her up into the air like a rag doll. It's shock, it's horror, disbelief.
MICHAEL USHER: There's even more disbelief and relief because both sisters are alive.
PC TRACEY COPE: The casualty I was dealing with, she was unconscious. I mean, you can see the damage to the vehicle windscreen and roof as well.
PC PAUL FINLAYSON: The first twin I went to had clearly sustained massive leg injuries. It's not something that they teach you when you go to police officer school.
MICHAEL USHER: What the hell were they running for? Exactly. The police and the road workers are all in shock as they try and make sense of what just happened. They believe the sisters are high on drugs or alcohol, but they're not. As you'll see, the most likely explanation is that they're suffering some sort of rare, and quite possibly, temporary mental illness. But, before we get to that, this story has many more strange turns.
PC PAUL FINLAYSON: What I couldn't understand at the time was that I've got a person who is smashed from the waist down but, from the waist up, is aggressive and violent and was spitting.
MICHAEL USHER: Ursula Erikkson is acting very aggressively but, because of her broken legs and severe internal injuries, can't move. Her sister, Sabina, unconscious just a few minutes ago, now comes to and, with an almost super-human display of strength, gets to her feet. What happens next is unbelievable.
PC TRACEY COPE: As I got her towards the car, she unleashed a punch and then she was off and into the other side, into moving traffic again. What on earth is she doing? Oh my God, we're going to have another incident on the opposite carriageway that's just happened here.
PC PAUL FINLAYSON: I don't know at this stage how violent her mindset was going to be. Soon found that out!
MICHAEL USHER: With the help of some very brave bystanders, the police finally wrestle Sabina to safety.
PC PAUL FINLAYSON: When I look back on it, her strength was phenomenal.
PC TRACEY COPE: She's almost waving us around like ragdolls on her arms.
MICHAEL USHER: Paramedics take over, sedating and restraining the agitated Sabina, so that she and her critically injured sister, Ursula, can finally be airlifted to hospital.
PC TRACEY COPE: When you look back, it's just so bizarre, so spontaneous, inexplicable.
MICHAEL USHER: In hospital, doctors fight to save Ursula's life but, remarkably, just five hours after being hit by a car, Sabina Erikkson is given the all-clear, and is discharged. Police officer Richard Elliott takes her into custody. He expects a fight, but Sabina's a completely different woman.
PC RICHARD ELLIOTT: You can honestly say that that person, that screaming banshee of a woman, is not the person that we picked up from the hospital. She's not tried to run off, she's not exhibited any aggression. I was quite happy that she could be conveyed without being handcuffed.
MICHAEL USHER: Sabina happily goes to the police station. There, she's friendly, and even flirts with the officer. Sabina is charged with assaulting police and trespassing on the motorway.
PC RICHARD ELLIOTT: I don't think she knew anything that had gone on. She either didn't care or couldn't remember. I can't understand how somebody appears so comfortable in that situation because I would be bricking it.
MICHAEL USHER: The police investigation revealed Sabina lived in Ireland with her partner and children. She had no previous convictions and no history of mental illness. Her sister, Ursula, had been living in America but visited Sabina in Ireland. From there, they disappeared for a day until turning up in Liverpool, England, on a bus bound for London.
DET. SUP. DAVE MELLOR: We still don't truly understand why the sisters chose to catch that bus for London. Sabina, in particular, never gave us any indication during any of the interviews that might have helped us understand the true reason for her and her sister visiting England. On the bus, the sister's behaviour was erratic, and the driver became concerned. At a rest stop halfway through the journey, he asked them to get off, calm down, and catch the next bus coming down the highway, but they didn't. Instead, for some reason, they set off on foot down the M6 Motorway, leading to that sickening game of Russian roulette with the traffic. But, as bizarre as that incident was, things were about to get a whole lot more tragic. Two days later, after pleading guilty to the charges against her, Sabina was released from the Stoke-on-Trent police station, in the British Midlands. Out on the street, she strikes up a conversation with an unsuspecting and friendly local, Glenn Hollinshead, who offers her a meal and a room for the night.
PETER MOLLOY: He was just being a good Samaritan. He'd seen someone that needed help. He was a really warm and helpful person. Her personality sort of opened up. She was a lot more bubbly and friendly,
MICHAEL USHER: Peter Molloy was Glenn's best friend. But, unlike Glenn, the more he got to know of Sabina and her story, the more he was worried.
PETER MOLLOY: I, personally, inside was getting quite paranoid and freaked out. There was this growing fear inside of me thinking, who is this woman? She's hiding from someone? So, I'm looking at Glenn for reassurance and he's like, "It's alright, it's alright."
MICHAEL USHER: But it wasn't. Less than a day later, Glenn Hollinshead was stabbed to death and, again, CCTV cameras captured the evidence - Sabina Erikkson running from Glenn's house carrying a large hammer, which, incredibly, she then started hitting herself with. A passing motorist, Joshua Grattage, tried to stop her.
JOSHUA GRATTAGE: Just put my hands straight on the hammer and lowered it, and I was just completely like zoned-in on the hammer. She was making crazy grunting noises the whole time - really primitive type of rage. She hit me on the back of the head with something, which I assumed was her fist, but I was told later by the police it was a roof tile that she had in her pocket.
MICHAEL USHER: Sabina overpowers Joshua and runs to the middle of a motorway overpass and, to everyone's horror, she jumps, falling 15 metres onto the road. She fractures both her legs and her skull but, defying belief, again she survived. Sabina was in hospital for three months, just like her sister. But, unlike Ursula, who moved back to America when she was discharged, Sabina was not freed. She was charged with the murder of Glenn Hollinshead, but detectives hoping to get answers and explain the sister's mysterious behaviour were left deeply frustrated.
DET. SUP. DAVE MELLOR: Sabina Erikkson chose to say "no comment" to every question that was put to her, so she has never given an account for any of her actions.
MICHAEL USHER: With the police at a loss, the court case against Sabina became very complicated. A number of psychiatrists determined that Sabina was mentally ill when she repeatedly ran into motorway traffic and when she killed Glenn Hollinshead. But exactly what that mental illness was left the experts baffled. Professor Nigel Eastman is one of Britain's leading forensic psychiatrists.
PROF. NIGEL EASTMAN: The first diagnosis is induced delusional disorder. It's common name, if you like, is 'folie a deux' and essentially it means 'madness in two people'. It's a very rare condition in which one person of the two has a recognised psychotic illness and the other person is, if you like, infected by it. They take on the abnormal beliefs of the person who is ill. Identical twins often have very close relationships so, psychologically, there's a sort of blurring of boundary of who is who.
MICHAEL USHER: The defence argued it was Ursula who had the mental illness and Sabina was infected by her sister's condition. But the prosecution disagreed, saying Sabina suffered from Acute Polymorphic Psychotic Disorder, which is like temporary insanity.
PROF. NIGEL EASTMAN: It's a transient psychotic illness where the person very abruptly becomes ill. It usually lasts for a short time, perhaps two to three weeks, and then goes away again.
MICHAEL USHER: The trial was as confusing as the events were bizarre. In the end, Sabina pleaded guilty to manslaughter and is serving five years in prison. But in the final twist of this remarkable story, all the psychiatric experts agree Sabina is no longer mentally ill, nor Ursula for that matter, who's living happily in America. What they can't predict though is what happens when the sisters are re-united, and that's a frightening prospect for the police, so traumatised by that day on the motorway.
PC PAUL FINLAYSON I still can't look back and actually understand what happened. I still can't understand how two people have the same mindset at the same time to such a degree to act together in a joint venture like this.
