Bath Literature Festival: Rights lawyer asks - just how much doubt is reasonable?

How do you quantify "reasonable doubt"? And how much doubt is enough to stop you sending a fellow human to prison or execution? There were weird scenes in Bath's historic Guildhall when the maverick human rights lawyer Clive Stafford-Smith, asking these questions, turned the banqueting hall into a court of law and the audience into a quaking jury.

The jury in the Vicky Pryce trial was condemned by many as stupid for asking the judge if they could reach a verdict based on speculation without evidence, but he was prepared to defend them. "They were asking for a ruling about reaching a verdict 'beyond reasonable doubt' and they were right to speculate. After all, how much do we think is reasonable doubt?" Whereupon he pushed a microphone in the faces of alarmed festival-goers and demanded they put a figure on it, on pain of "being held in contempt – by me!" Two said "100 per cent," one said 99, another said 98. "I put the question to judges in Louisiana," Stafford-Smith said. "They said about 80-ish."

His point was that, if there's a smidgen of doubt that an accused person isn't guilty, he shouldn't be condemned. For 26 years Stafford-Smith has been fighting a miscarriage of justice in Florida, where a British businessman named Kris Maharaj was arrested for shooting a father and son in a hotel room. A witness testified that he'd seen the shooting, and passed a polygraph test. Maharaj's fingerprints were found in the room. It was proved that he owed the dead men money and that he'd recently bought a gun. A witness said he'd asked him to supply an alibi.

So, said Stafford-Smith, is he guilty or innocent? Most of the audience raised their hands. The defence lawyer on stage spent the next 55 minutes explaining why they were presumptuous, wrong and rather dim to reach such a conclusion. Stafford-Smith strides the stage with awesome command, bullies and harangues his audience, who shifted uncomfortably as he demanded to know their opinion, demanded they role-play jurors and accused, and insisted they would be locked in until they promised to help him in his campaign. By the end, they felt they'd much rather have this rambunctious brief on their side than not.