Killers tell all for fame or parole: Michael Sams's post-trial confession was to show he was 'not brutal', but motives of others vary, Terry Kirby reports

FOUR years after the unanimous guilty verdict of the jury, John Cannan continues to deny any responsibility for the series of crimes for which he was convicted - the murder of Shirley Banks from Bristol and the rape and attempted abduction of two other women.

Sentencing Cannan, Mr Justice Drake, expressed his horror of the crimes by saying Cannan should be jailed for the rest of his natural life. In doing so, the judge removed any possibility that Cannan would make a post- conviction admission to hasten his release or improve his conditions in prison.

Among the convictions which Cannan denies is the rape of a woman in Reading for which there was overwhelming DNA evidence. This put the odds of him not being the offender at 260 million to one. Cannan has also denied the murder of the missing estate agent, Suzy Lamplugh, for which there is strong circumstantial evidence to link him. Police realise there are no incentives they can give him.

Constable Ian Gibson, of Avon and Somerset Police, who liaised with the Banks family throughout the case, believes that, as in the Michael Sams affair, a post-trial confession is an aid to the healing process for victims' relatives. 'I am sure that such admissions help relatives through the bereavement process. It can be important to know exactly what happened.'

Quite why Sams has now confessed to the murder of Julie Dart, after denying it from the moment of arrest and throughout his four week-trial, remains unclear. His explanation - that he wanted Julie Dart's mother to know the date of her daughter's death - may be just part of the story.

Paul Britton, a clinical psychologist who advised detectives interviewing Sams, said yesterday: 'Sams is a games player and is now playing the game of compassion. He wants very clearly to show that he is not this brutal man; he perhaps wants to explain the murder away as some tragic mishap.'

During the trial, he expected the lawyers and the jury to interpret small details in his favour despite the entirely contradictory evidence.

Mr Britton, who has interviewed many serial offenders, believes the Sams case is a rarity: 'Very often, offenders find it very difficult to acknowledge and accept that they have been telling all these lies,' he said.

However, many of the most recent killers do not deny their crimes. Dennis Nilsen, the strangler of homosexual youths, made a full admission within minutes of arrest and pleaded guilty at his trial; Peter Sutcliffe, who, unlike Nilsen or Sams, is classed as criminally insane, also now freely admits his murders. For these, the incentive is not release, but fame.

The most powerful incentive is the prospect of release, which is why admissions of guilt tend to come from those hopeful of parole. Despite their admissions, Sams and Nilsen have no prospect of release until they are very old men; Cannan has almost none at all.