Mr Garces, is owlish, aged 55, dry and undemonstrative, but he spreads his hands in a rare expressive gesture as he replies: "In legal terms we expect him. We expect Britain to grant extradition. But as with all legal decisions, we can only speculate. Who knows what's inside the head of a judge?"
The answer is typical of his style, deflecting questions inviting opinion or personal reflection into strictly legal channels.
Mr Garces was an adviser to President Salvador Allende when General Pinochet's forces bombed the presidential palace in Santiago, Chile, on 11 September 1973, causing Allende's death. The young Spanish lawyer, among the last to see his boss alive, slipped to safety thanks to the intervention of the Spanish ambassador. He has been working patiently ever since to bring Pinochet to trial for human rights abuses, and tomorrow, in Bow Street magistrates' court, London, extradition proceedings will begin.
But Gen Pinochet has already been under house arrest in Britain for a year, and legal procedures could drag on much longer; some expect him to end his days in the UK. Some suggest he has already been condemned - morally - and humiliated, and that maybe it's time to drop the whole thing.
"Justice takes time, but it gets there. For years, in the Cold War, the international community closed its eyes to crimes against humanity that international agreements could have punished. You do justice when you can."
The lawyer himself is in no hurry. He has spent years gathering harrowing testimonies from families of Gen Pinochet's victims who despaired of ever getting justice. The cases form the bulk of the indictment drawn up by Judge Baltasar Garzon who ordered Gen Pinochet's arrest in London last October and seeks his extradition to Spain.
Mr Garces sums up the transformations of the past year. "The decision of the Spanish courts to apply international treaties signed by Chile, Spain and Britain against torture and genocide as universal crimes has had a ripple effect through the world. France, Belgium, Switzerland and Italy seek extradition, German and Canadian prosecutors are preparing cases. The US Justice Department is investigating a possible link between Pinochet and the murder of the US citizen Ronnie Moffitt and of Chile's former ambassador, Orlando Letelier."
After years of paralysis, even Chile's legal system is now making advances. "Chile's judiciary has recovered important freedoms, and generals have been detained - until now complaints against them were invariably shelved. No one in Spain disputes Chile's right to try Pinochet. But they must seek his extradition and not use that as an excuse to free him."
Crimes attributed to Gen Pinochet are so serious they can never expire, nor go unpunished, Mr Garces believes. That the man is 83 alters nothing, he argues. In recent years, octogenarian Nazis have been sentenced in France for their crimes of the 1940s. "Pinochet's crimes are of the same magnitude - including torturing with a blowtorch."
Spain's extradition request lists three groups of victims - the 1,198 kidnapped by Pinochet's agents, the tortured, and the "disappeared" (including a Briton, William Beausire). Disappearance constitutes torture under international law, Mr Garces argues, and is a "permanent crime" since the bodies are still missing.
The list includes six people tortured to death, and some 50 who were tortured but survived. All the cases occurred after September 1988, when Britain signed the international convention on torture.
The justice system has a duty to resolve the cases however long it takes, says Mr Garces. "To seek Pinochet's freedom on humanitarian grounds is to subvert the fundamental principle of national and international law, because these aren't ordinary crimes, they are the worst it is possible to commit."Reuse content