"Have you told the truth today?" The first question put to Gareth Dack under cross-examination from prosecutor Christopher Tehrani, QC, could just as easily have been the last.

During three days in the witness box, the 33-year-old murderer repeatedly tied himself in knots with his lies, forgetting what he had said and written earlier.

At times it was an embarrassingly bad "performance" from a man who thought he was far more clever and cunning than he really was - and the jury saw it all too clearly.

The panel of six men and six women at Teesside Crown Court took just ?L to convict debt-ridden Dack of strangling Mrs Bell before setting fire to her Hartlepool home.

His DNA was all over the terraced property, he sold a television stolen from the house, and despite being so hard-up he was borrowing tenners from "all-comers" he had more than £400 in the glovebox of his car.

That silver Volkswagen Bora was parked opposite Mrs Bell's home in Westbourne Road when firefighters arrived at around 8.30am on Sunday, April 3 last year.

An emergency mobile phone used by mother-of-nine Mrs Bell was found in the garage at the home of Dack's parents - further down the same street.

Dack's footprints were found on the lid of a wheelie bin, which he climbed on to scale a wall in the back yard in a bid to leave the property unnoticed after the murder and arson.

He had turned on gas hobs on the cooker, hoping to cause an explosion to destroy any evidence that might link him to one of the North-East's most disturbing murders in recent years.

The dad-of-four changed his story time after time when he was confronted with new facts which proved he was the killer, the person who stole the brand new boxed 49-inch television, the mobile phone, £700 from a bedroom and phoned adult sex lines from the house.

He said he had been dealing cocaine from his parents' garage the night Mrs Bell was throttled, bought the TV from a mystery man who walked past, had been loaned the phone, and had carried out a job in the back yard which required him to stand on the bin.

Had not been such a shockingly serious case, his defence would have been laughable.

Prosecutor Mr Tehrani said Dack was "nonchalant" when he'd been arrested, bothered more about his cigarette than facing a life sentence for murder.

He countered that with the "fact" that he was in shock after being picked up for a crime he had not committed.

Again, the jury saw his lies for what they were.

Time after time - when his account from the witness box did not match what he had earlier put in a defence statement or given in evidence - he said: "It should be in there."

With a heavy hint of sarcasm, Mr Tehrani described as "another unfortunate coincidence" all the things that pointed to Dack as the killer of Mrs Bell, who had fostered more than 50 children with her late husband John.

During the lengthy cross-examination, the prosecutor put it to Dack: "The truth here is that you lie when it suits you. You will lie, you will lie and you will lie if it gets you out of a fix."

A former friend who spoke to The Northern Echo said the barrister's assessment was "spot on".

They said: "He's always been full of s*** - a real Billy big-bollocks. He always thought he was better than everyone else, bragging about what he had and what he had done. We all knew it was bull****."

Out-of-work asbestos lagger Dack used similarly industrial language - but, as he learned during an strong rebuke from the trial judge, a courtroom is not like a bar room, and not the place for profanities.

He accused the prosecution of "taking the p***" as Mr Tehrani quizzed him about DNA evidence on the 11th and most tetchy day of the trial, sparking an angry Mrs Justice Whipple to order him to "observe decency".

Incredibly, Dack repeatedly refused to name the person who had given him £300-worth of cocaine on tick to sell, or any of the customers who bought it.

Despite being told it would provide him with an alibi for the murder, and help him avoid a potential life sentence, he smugly told Mr Tehrani: "I can't be convicted of something I haven't done, I'm afraid."

The jury thought differently. They didn't believe the unbelievable. They saw through the tissue of lies.