Gary McKinnon: The big questions answered Why has Gary McKinnon's extradition been blocked? A new review by Home Office-appointed psychiatrists supported his mother Janis Sharp's claim that the 46-year-old Asperger's Syndrome sufferer was at significant risk of suicide if sent for trial in the US. Home Secretary Theresa May has blocked extradition, saying that the danger of self harm was so great it would be incompatible with his human rights. Why does the United States want him extradited? The Americans accuse him of "the biggest military computer hack of all time" though he insists he was simply looking for evidence of UFOs. His supporters have repeatedly said that the allegations should go before a UK court as he was in this country at the time. What are the new proposals? A forum bar will be introduced. Where a trial is possible in both the UK and abroad, British courts will have the power to bar prosecution overseas if they believe it is in the interests of justice. It is also proposed that appeals on human rights grounds will be passed from the Home Secretary to be judged by the High Court instead. What has been the reaction? Campaigners have welcomed the "long-awaited reforms" as "refreshing," insisting they will put "justice and fairness back into our extradition laws." Others, however, remain cautious, saying the "devil will be in the detail" and that the term "interests of justice" is "woolly." Experts assess that judges are still likely to extradite unless the presumption is set down that the onus is on the requesting state to prove trial should be abroad. When will it come into effect? Both proposals are, according to the Home Office, at the "early stages." They will require primary legislation, which will take many months to pass through expert analysis and then parliament. Why is this different from the case of five recently extradited terror suspects? Mrs May has said this case has been decided on the human rights issue alone and that she still accepts the US-UK extradition treaty is balanced. She cited the deportation of Abu Hamza, who was sent to America 10 days ago along with four fellow suspects, as an example of how it works well. However, supporters of Babar Ahmad and Syed Talha Ahsan accuse the Government of "blatant old-fashioned racism," pointing out the similarities in the cases as they were using computers in the UK and the latter also has Asperger's Syndrome. Will the forum bar drag out extradition cases even longer? A review of the UK's extradition proceedings by retired Court of Appeal judge Sir Scott Baker last year found existing forum legislation would lead to delays and satellite litigation. But Mrs May said proposals to reduce long delays in extradition cases would be considered while draft guidance for prosecutors handling cases which cross jurisdictions will also be drawn up. What impact will this have on current cases? It remains to be seen how much impact it will have on cases such as that of Richard O'Dwyer, 24, who is fighting extradition to the US accused of infringing copyright laws by earning thousands of pounds advertising on the TVShack website before it was closed down. Mrs May was keen to emphasise that Mr McKinnon's case was "exceptional" and that she still believed that the current US-UK extradition treaty was fair. It remains to be seen whether any new legislation is introduced in time for Mr O'Dwyer as the Home Office has said cases will not be held and new laws will not be retrospective. What impact will this have on future cases? While it is hoped that more cases will be tried in the UK under the Government's plans to give British courts greater influence over extradition proceedings, experts assess that there will still be a presumption in favour of the requesting state unless new legislation states otherwise. What about extradition to Europe? Mrs May also said the Government was considering opting out of all pre-Lisbon treaty police and criminal justice measures, including the European Arrest Warrant. Opponents of the EAW welcomed the decision, insisting it has led to cases of serious injustice because it has removed the traditional safeguards. Others, however, claim such a move will hamper Britain's ability to fight crimes such as terrorism and drug trafficking without measures for swift extradition of suspects to and from the UK. It is now for the director of public prosecutions Keir Starmer QC to decide whether he should face trial in the UK.