Jill Dando murder trial: Experts were split on Barry George's behaviour

Experts called by the prosecution and defence came up with rival theories to explain his behaviour.

Neuropsychiatrist Professor Michael Kopelman said tests of George's memory and ability to plan and execute tasks put him in the bottom 1% of the population.

He also found it difficult to foresee the consequences of his actions, the professor said.

During the height of the Troubles in the early 1980s, George had gone to his sister's wedding in Ireland and claimed he was in the SAS – a boast that came close to getting him beaten up, he added.

Scans showed "severely abnormal" activity in George's brain, the professor said.

George, an epileptic, suffered prolonged "absence attacks" that could last hours during which he lost awareness of what was going on around him.

William Clegg QC, defending, described his mental state as a "lightbulb flickering" and "only a 40-watt bulb when it is completely lit".

He said "our Barry", the "local nutter" with serious psychological problems did not have the capability to carry out the meticulously-planned murder.

However, Dr Philip Joseph, another leading psychiatrist who was called by the prosecution, said George was "far more competent" than tests would suggest and capable of lying in police interviews.

While some of his behaviour could be attributed to his epilepsy and cognitive impairment, his stalking of women appeared to stem from an "intense anger" caused by rejection, Dr Joseph said.

He also said that George developed a "fantasy world" in which he believed he knew famous people.

GEORGE 'OBSESSED' WITH PRINCESS OF WALES

BARRY George was said to be obsessed with the Princess of Wales – and it was claimed after her death that he switched his fixation to Jill Dando, a woman whose blonde good looks were similar to those of Diana.

Barry George was once arrested in combat gear outside the London home of the princess, carrying a length of rope and with a knife in his belt.

He was discovered hiding in bushes, but no charge resulted and Diana, who was still married to the Prince of Wales, is thought to have been away at the time of the incident in 1983.

George was also known to have stood among mourners at Diana's funeral in 1997 when he proudly held up a poster dedicated to his "Queen of Hearts".

He signed the placard "Barry Bulsara, Freddie Mercury's cousin".

Detectives searching George's flat after Dando's murder found registration numbers of two of Diana's cars.

The incidents were said to be further evidence of George's obsessive behaviour towards famous women – behaviour he was alleged to have focused on Dando after Diana's death.

Dando's striking similarities to Diana may have appealed to him, a forensic psychologist said.

Stalking expert Dr John Reid Meloy said in 2001: "I became aware through photographs of Jill Dando prior to her death that she was very similar to Princess Diana.

"Her public persona invited affectionate feelings by the audience or by the viewer, the same as Princess Diana.

"Here is a woman who is very open, affectionate, extroverted, who communicates affection to other people and when people do that, they tend to invite that same kind of reaction.

"Sadly these are also the kinds of women in public life who are stalked."