Most confessions made immediately after arrest: The British Psychological Society's conference in London

WHAT happens in the back of police cars has more bearing on whether a crime suspect confesses than the 'so-called' interrogation skills of police officers, research has revealed.

Dr Stephen Moston, a psychology lecturer, told the winter meeting of the British Psychological Society in London yesterday that the emphasis in police training on interviewing techniques was 'absolutely useless'. Dr Moston, of the University of New South Wales in Sydney, Australia, said that quite different influences determined whether a guilty suspect confessed.

In a study of 604 arrests made by police in Cumbria, Bedfordshire and London, he found that 82 per cent of suspects confessed when they had been interviewed informally between the arrest and arriving at the police station, compared to 56 per cent who had not had these conversations.

'Something is going on that influences their behaviour, some kind of rapport is being built. The discussions were often about bail or sentencing and usually it is the suspect who strikes up the conversation,' he said. Dr Moston said later that there was no implication that there had been any impropriety on the part of the police during the informal interviews, but the research had, for the first time, provided evidence of their importance.

Another study of 1,000 confessions from Metropolitan Police records showed that when confessions occurred they were early in the formal interview and that strong evidence was most likely to produce a confession. He said the more severe the offence, the more likely the suspect was to claim the right to silence, and that this likelihood was increased when a legal adviser was present.

'All this leads to a conclusion of how important it is to get decent evidence before police start the formal interview. The most important thing police can be taught is how to ask logically constructed questions in a non-aggressive way.'

Dr Moston said there were great dangers in movements towards videoing formal police interviews and downgrading the need for corroborative evidence. 'Police officers themselves are starting to tape these discussions before the suspects arrive at the station,' he said.