UN High Commissioner for Human Rights Louise Arbour said on Tuesday planned Guantanamo war crimes trials fell short of international standards and handing down death penalties would be "just not acceptable".
In an interview with Reuters before leaving office on June 30, the former UN war crimes chief prosecutor chided the administration of US President George W. Bush for last week's decision to distance itself from the United Nations Human Rights Council.
It was much too soon to write off the Geneva forum set up two years ago, in which Washington could play an important role in defusing a perceived confrontation between members of the European Union (EU) and Islamic countries, according to Arbour.
The former Canadian Supreme Court judge, 61, is going home after deciding not to seek a second four-year term. Arbour has long denounced the system created by the Bush administration to try suspected al Qaeda operatives outside regular civilian and military courts, and alleged torture and secret renditions conducted in the US-led "war on terrorism".
"In a process where the definition of a crime is somewhat more ambiguous, the standard of proof is lowered, the capacity to make a full answer of defence is lowered, the chances of wrongful conviction necessarily increases," Arbour said.
"So to add the death penalty to that, it seems to me, is just not acceptable," she said of the Guantanamo trials. Arbour said international human rights law permitted the death penalty for the most serious crimes if trials are fair.
"There has to be impeccable due process, the process has to meet the highest standards of fairness," she said. "Frankly, I think the military commissions... fall short in many respects."
Shortcomings at Guantanamo included insufficient access to evidence by the defence. "I think the process is not adequate to justify recourse to the death penalty." The Pentagon has declared the trials a national priority and is doubling the number of military lawyers assigned to them even as critics say the government is rushing because it wants to influence US presidential elections in November.
Air Force Brigadier General Thomas Hartmann, legal adviser to the Pentagon appointee overseeing the trials, told journalists visiting the US naval base in south-eastern Cuba on Sunday that providing "fair, just and transparent trials" was its top duty.
Five accused al Qaeda prisoners who could be executed if convicted of plotting the September 11 attacks, which killed nearly 3,000 people, appeared in court there for the first time last week after spending about three years in secret CIA prisons.
Even in trials held under a rigorous judicial system with proper defence, wrongful convictions can result, according to Arbour, an expert on Canadian and international criminal law.
The US State Department said last Friday that it would disengage from the UN Human Rights Council, except when there was an issue of "deep national interest". Arbour said US concerns included the Council's "perceived fixation on the Middle East" and several resolutions dealing specifically with alleged abuses by its ally Israel.
But she suggested it was "premature to send such a negative signal" just as the 47-member forum has begun examining the rights records of all states. The innovative mechanism known as the Universal Peer Review is meant to overcome double standards. "The sooner we can persuade the Americans to join the Council and reengage more fully, the better," she said.