Ursula Eriksson and Sabina Eriksson (born 3 November 1967) are Swedish twin sisters who came to national attention in the United Kingdom in May 2008. The twins had been in Ireland before travelling to the UK and boarding a bus for London in Liverpool. Their odd behaviour after exiting the bus at a service station on the M6 motorway caused the driver not to allow them back on board. The two were later seen on the central reservation of the M6 motorway. When Highways England traffic officers arrived to assist the women, they ran across the busy motorway, as captured by a small television crew. Ursula managed to dodge traffic, but Sabina was knocked over. Shortly after police arrived, the women again dashed onto the motorway and were struck by oncoming vehicles. Ursula suffered serious injuries, and when Sabina regained consciousness, she refused medical aid and attacked a police officer, at which point she was arrested and sedated.
Appearing calm, though behaving unusually, Sabina was processed by police in Stoke-on-Trent and was later released from custody. Shortly afterwards, she was seen and taken in by Glenn Hollinshead, of Fenton, Staffordshire, whom she suddenly stabbed to death the next day. Sabina was then pursued running from the scene and arrested in hospital after jumping from a bridge onto a busy trunk road. Despite these incidents, there was no evidence that drugs or alcohol were involved in the incidents on the M6 or the killing of Hollinshead.[1][2][3] Sabina later pleaded guilty to manslaughter with diminished responsibility, after an apparent episode of folie à deux (or "shared psychosis"), a rare psychiatric disorder in which delusional beliefs are transmitted from one individual to another. As identical twins sharing the same genetic makeup the chances of such a psychiatric disorders may be increased. Ursula was released from the hospital after recovering and now lives in Bellevue, Washington, US, but Sabina was sentenced to five years imprisonment and released on parole in 2011 before returning to Sweden.[3]
why was invoked but never defined (see the help page).