The Home Secretary Theresa May announces that computer hacker Gary McKinnon will not be extradited to the US to face charges.
The home secretary said she had taken extensive legal and medical advice and decided to halt extradition proceedings.
Ms May stopped his extradition on human rights ground after medical reports showed the 46-year-old was very likely to try to kill himself if sent to the US.
Steps will now be taken to see if Mr McKinnon will face charges in the UK.
46-year-old McKinnon, who suffers from Asperger’s syndrome – a high-functioning form of autism – admits hacking into US military computers but claims he was looking for evidence of UFOs.
Speaking at a press conference, his mother Janis Sharp said she was “overwhelmed” after an “emotional rollercoaster” and she said Mrs May had been “incredibly brave” to “stand up” to the US.
Mr McKinnon, 46, admits accessing US government computers but claims he was looking for evidence of UFOs.
The home secretary told MPs McKinnon was “seriously ill”.
Ms Sharp said her son could not speak when he first heard of the decision but then he cried and hugged her.
She said: “He felt like he was a dead person. He had no job, he didn’t go on holiday… he felt worthless.”
His solicitor, Karen Todner, said it was “a great day for British justice” and his barrister, Edward Fitzgerald QC, said Mrs May had been “brave”.
Asked about the possibility of a trial in the UK, she added: ‘He’s lost 10 years of his life, but if this happens as well, we can deal with that.’
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Shami Chakrabarti, director of civil rights group Liberty, said: “This is a great day for rights, freedoms and justice in the United Kingdom.
“The home secretary has spared this vulnerable man the cruelty of being sent to the US and accepted Liberty’s long-standing argument for change to our rotten extradition laws.
“Extradition should prevent fugitives escaping – not allow for Britons like Gary to be parcelled off around the world based on allegations of offences committed here at home.
“This campaign, led by Gary’s fearless mother, united lawyers, politicians, press and public from across the spectrum in the cause of compassion and common sense.”
Ms May also said that in future, similar decisions should rest with courts rather than the government: “I also agree with the Baker review‘s recommendation that the breadth of the home secretary’s involvement in extradition cases should be reduced.
“Matters such as representations on human rights grounds should, in future, be considered by the high court rather than the home secretary. This change, which will significantly reduce delays in certain cases, will require primary legislation.”
The ups and downs of his fight have been so cruel they amount to “waterboarding of the mind”, McKinnon’s mother Janis Sharp had said.
Home Office medical evidence showed McKinnon would be very likely to try to kill himself if extradited to the US, where he would face up to 60 years in prison if convicted.
Prime Minister David Cameron had raised McKinnon’s case with US President Barack Obama twice “and each time I thought we were nearly home and dry but nothing happened”, Ms Sharp added.
“I’m more optimistic now. I don’t see how they could say that in evidence and then extradite,” she said.