Computer hacker Gary McKinnon's 10-year fight against extradition to the United States was an "emotional rollercoaster", his mother has said.
Janis Sharp said she was "overwhelmed" after Home Secretary Theresa May used the Human Rights Act to halt her son's extradition to the US.
McKinnon was accused by US prosecutors of "the biggest military computer hack of all time", but he claims he was simply looking for evidence of UFOs.
A spokeswoman for the US justice department told The Huffington Post UK: "The United States is disappointed by the UK Home Secretary’s decision not to extradite Gary McKinnon, particularly given the past decisions of the UK courts and prior home secretaries that he should face trial in the United States.
"We note that the home secretary has described this case as exceptional and, thus, this decision does not set a precedent for future cases," she added.
When she told her son of the decision, Ms Sharp said: "He literally couldn't speak, then he cried, there's been hugging and crying. It's been so emotional.
"He had just shut down. It was just the waste of talent - 10 years. It was very good to see him smile for the first time in many years.
"I want to say thank you to Theresa May because it was an incredibly brave decision - to stand up to another nation as strong and powerful as America is rare and she had the guts to do it.
"I always felt that she had the strength to come through and do this and to also change the extradition treaty to bring in forum so hopefully that this won't happen to anybody else.
"It's absolutely incredible."
She added: "Without the support we could never have done it. Gary is here because of all this."
"I know it's been a life-saving decision because Gary doesn't travel abroad, he doesn't go on holiday, he very rarely leaves north London, and to be taken from everything you know, your family, everything, thousands of miles away is so terrifying to him," Ms Sharp said.
"I can understand that he felt he would rather be dead."
It will now be for the director of public prosecutions (DPP) Keir Starmer QC to decide whether McKinnon should face charges in the UK.
McKinnon's lawyer Karen Todner said it was "a great day for British justice" and added that she hoped the DPP "might consider that Gary has suffered enough".
Edward Fitzgerald QC, who represented McKinnon, praised Mrs May for using the Human Rights Act to halt the extradition.
"It was only thanks to the Human Rights Act that she had the power to stop this extradition," he said.
David Burrowes, McKinnon's MP, said: "It's a life that's been given back to Gary in a long dark tunnel that is 10 years.
"This must never happen again."
Ms Sharp said her 46-year-old son could not speak when he heard the news because he was so emotional.
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."
Ms Todner added that Mr McKinnon has "done more than his sentence, in my view, but obviously that's a decision for Keir Starmer".
Medical evidence may even suggest that he is unfit to enter a plea, she said.
Sting's wife Trudie Styler, who backed the campaign against Mr McKinnon's extradition, said: "I am delighted that after all the years of wrangling and uncertainty - which, in themselves, have taken a terrible toll on Gary's already poor health - the Home Secretary has shown the humanity and courage to reach this decision.
"As a mother I applaud the steadfast love and support which Janis has given her son as she has fought every inch of the way against Gary's extradition to the USA."