He is a silver-haired exiled Argentinian businessman who lived a quiet life in Mexico, running the country's national car registry. But yesterday the former naval officer was bundled into a bullet-proof vest, handcuffed and flown in a Spanish air force Boeing 707 across the Atlantic to face genocide and terrorism charges in Spain.
Ricardo Cavallo, accused of being one of the worst torturers of Argentina's "dirty war" between 1976 and 1983, exhausted all avenues of appeal last week, when Mexico's Supreme Court agreed that he could be extradited to Spain.
Mr Cavallo had lived untroubled for years in Mexico until a newspaper challenged his identity and he was detained in 2000 in the Mexican resort of Cancun, on his way to Argentina. He had been accused by five former political prisoners of being a former "dirty war" intelligence agent who went by the aliases "Serpico" and "Marcelo".
The case has been hailed by human rights activists as a landmark. He will become the first person to face trial for crimes not committed in the country of jurisdiction. Mr Cavallo will therefore be unprotected by an amnesty in his native country offered to those accused of repression under the dictatorship of General Leopoldo Galtieri.
Up to 30,000 people were killed or "disappeared" in the Argentine military's war against leftist guerrillas and their sympathisers. Many were tortured, drugged and in some cases thrown from aircraft into the River Plate or the Atlantic Ocean.
Mr Cavallo, 51, is accused of having worked as a member of a crack operational unit in the notorious School of Naval Mechanics in Buenos Aires, a secret torture centre under General Galtieri.
Accompanied by officers from Interpol and the Spanish police, Mr Cavallo was driven from Madrid's Torrejon de Ardoz air base in a convoy of police vans to appear at a specially convened session of the National Court yesterday morning, where he was arraigned by the crusading Spanish judge Baltasar Garzon.
Mr Garzon campaigned unsuccessfully to bring the former Chilean dictator General Augusto Pinochet to trial in Spain five years ago. But in the Cavallo case, the extradition request was filed under the terms of a bilateral extradition treaty, rather than an international rights agreement, which led to the failed effort to bring Pinochet to trial in 1998. At yesterday's five-minute session, during which the bespectacled defendant declined to testify, Mr Garzon handed over a 200-page report in which Mr Cavallo is accused of 200 cases of disappearances, 120 of kidnappings and 100 of torture dating from the "dirty war".
He will be tried in Spain for his alleged involvement in the torture of Thelma Jara, and for the murder of the Spaniards Monica Jauregui and Elba Delia Aldaya, and will face further charges of falsifying documents, according to the Spanish media.
Manuel Olle, a lawyer representing the victims, said the examining magistrate would call for the testimony of Marcelo Hernandez, an Argentinian who was tortured at the School of Naval Mechanics. Mr Hernandez, who was kept and tortured for two years at the centre, said: "I never dreamt of a day like this. The type of men who have been responsible for many deaths cannot be free."
As the prison van rolled up to the court, a group of some 100 Argentinian human rights activists, exiles and torture victims chanted, waving placards with the message "Universal Justice for the Victims of Torture" and "Extradition for the 48 Argentinian Authors of Genocide".
"It's a historic moment for all humanity," Ricardo Hausdorff, an Argentinian trades union and human rights activist, said outside the courthouse. "At long last a precedent has been set so that justice can reach any point in the world."
As excited demonstrators jostled with the police, Mr Hausdorff, 45, said exiled Argentinians regarded the detention as "a positive first step. The names of a further 48 Argentinians have come to light [in investigations of rights abuses] and we want them to be brought to book."
For some gathered in the heat outside the courthouse in central Madrid, the arraignment raised hope that it would challenge the longstanding impunity enjoyed by former torturers and dirty war functionaries within Argentina.
The documentary film maker Alcides Chiasa, 55, told The Independent he was tortured in Argentina's notorious Pozo de Quilmes detention centre "every six to eight hours" for a period of one month after he was kidnapped by military authorities in 1977. "They attached electrodes to me and also gave me 'the submarine' - a technique where they hold you underwater until you nearly drown - and they kidnapped my wife and father," he said.
"Cavallo's arraignment opens the door to justice and a full civil investigation in Argentina, so that the families of the disappeared can finally bury them," said Mr Chiasa as he waited for the van bearing Mr Cavallo to arrive at the court. "It gives us the hope that, after so many decades, we are finally going to see justice."
A spokesman for the National Court said Mr Cavallo had denied all knowledge of the crimes for which he was charged, and refused to sign a court document setting out his rights. Mr Garzon then adjourned the court until later in the day to give Mr Cavallo time to read the indictment against him.
Mr Cavallo, who was described as calm and collected at the hearing, has acknowledged that he was in Argentina's military, but he has denied involvement in torture. He was kept in a Madrid jail last night.
The Mexican Supreme Court, which issued its decision on 10 June, threw out torture charges against Mr Cavallo because the statute of limitations had expired.
Mr Garzon, 48, is one of six investigating judges for Spain's National Court. His function is to investigate the cases that are assigned to him by the court, gathering evidence and evaluating whether the case should be brought to trial. He does not try the cases.
The judge, who was nominated for the Nobel peace prize in 2002, has launched formal investigations into human rights abuses committed under the former military dictatorships of Chile and Argentina, and has brought charges against officials for the deaths of Spaniards in both countries.
Mr Cavallo is one of 98 military and civilian figures of the Argentine regime indicted by Judge Garzon last year. But most of them live in Argentina, where they are protected by the local amnesty laws.
Mr Garzon has been in charge of some of Spain's biggest cases, involving drug trafficking, corruption, the Basque terrorist group Eta and the GAL, a shady official hit-squad formed to fight Eta.
THE CLOSING NET
Known as "Africa's Pinochet", the exiled ruler of Chad was indicted on charges of torture and crimes against humanity by a court in Senegal in February 2000. In March 2001 the case was dropped after a ruling that Senegal could not prosecute crimes beyond its borders. Buthe might still be tried in Belgium, which is seeking his extradition.
In October 1998 the former Chilean dictator was arrested in London for extradition to Spain to face charges over the murder of Spanish nationals during his rule from 1973 to 1990. The extradition was stopped after it was ruled he was medically unfit to stand trial. He returned to Chile in March 2000, where he has been declared mentally unfit for trial.
Israel's Prime Minister has been accused of responsibility for the 1982 massacre of Palestinians at the Sabra and Shatila refugee camps in Lebanon, when he was Defence Minister.In February the Belgian Supreme Court decided to allow a case to be brought against Mr Sharon. Planned changes to Belgian law mean the case will not go ahead.
On trial at the United Nations tribunal in The Hague, Slobodan Milosevic is the first serving leader to be indicted for war crimes. The former Yugoslav president was arrested in April 2002 - two years after his indictment - and is accused of genocide and crimes against humanity in Bosnia, Croatia and Kosovo.