Despite US Supreme Court rulings outlawing the coercive questioning of suspects during interrogation, between 50 and 60 per cent of police interviews in the United States still produce a confession, a conference on psychology and law has been told. This is a reduction of between 10 and 15 per cent on previous confession rates.
Prof Chris Slobogin of the University of Florida was describing the effects of the adversarial system of justice on police procedures. He said it was not clear whether the high confession rate resulted from other kinds of coercion, deceit and trickery, or "a well-intentioned desire on the part of the suspect to help the police".
The international conference, which has brought over 500 delegates from five continents to Dublin this week, was opened by the President, Mrs McAleese, yesterday. The organiser, Prof David Carson of the University of Southampton, was a class-mate of the President's at Queen's University Belfast, she told the delegates.
A feature of the conference is a day-long "trial", presided over by Mr Justice Moriarty, which is exploring the relative merits of the Anglo-American adversarial system and the European inquisitorial system. As a High Court judge Mr Justice Moriarty presides over a court based on the adversarial system, but the tribunal of which he is chairman and sole member operates more in line with inquisitorial methods.
Prof Slobogin said that some kind of deceit and trickery during interrogation was allowed by US law. He also said the American system relied quite heavily on guilty pleas, and allowed a huge differential in sentencing between guilty and non-guilty pleas.
Dr Aldert Vrij of the University of Portsmouth said that deceit and trickery were unlawful in many countries, including the Netherlands. They could and did lead to false confessions, he said. "People can start to believe they committed a crime if they are told the evidence is there."
The US system assumed that people did not want to talk, he said, which was not true, 80 per cent of those questioned by police do want to talk. It also assumes that the suspect is guilty, which is not necessarily true either.
In the Netherlands, there was no plea-bargaining. Police interviews had to be prepared very, very well.
Both Prof Slobogin and Dr Vrij were among the "witnesses" called by Profs Steve Penrod and Peter von Koppen, who presented the cases for the American and Netherlands systems.