Vancouver Never mind that 'Mr Big', a supposedly all-powerful Canadian criminal mastermind, is a complete fiction. He has proven to be an effective weapon for police departments across the country, helping secure confessions from gullible crooks eager to impress such an important gangland figure. Mr Big, who had previously featured in several cases, has popped up again in the Vancouver trial of Nathan Fry, a 20-year-old charged with five counts of first-degree murder. Adela Etibako, three of her children and the girlfriend of her teenage son were all sleeping when a fire ripped through the family's home on May 15, 2006. The city's police chief said that if it was arson, as suspected, it was one of the worst crimes committed in Vancouver. Almost immediately after the fire was contained, investigators said they suspected it had been deliberately set. But it wasn't until more than a year later that Fry was arrested and charged. Fry, who has pleaded not guilty, was a friend of Bolingo Etibako, Adela Etibako's teenage son. But the pair had a falling out. Bolingo was the only person to escape the fire, but he spent nearly three months in hospital recovering from his burns. In the crown's opening statement against Fry, police were revealed to have used the so-called Mr Big sting operation to get their confession. Fry had apparently revealed detailed knowledge of the fire set in the Etibakos' low-income townhouse in east Vancouver, prosecutor Kerr Clark said. 'He couldn't reveal these things without being involved in the crime,' Mr Clark told the jury. 'The theory of the crown in this case is that the accused, Mr Fry, deliberately poured gasoline into the family room.' Fry then lit the petrol, according to the prosecution. The jury has not yet heard from the defence. But the validity of the alleged confession is likely to come into question, taking into account previous controversy over the technique. The exact details of Fry's confession are not known, but in general the Mr Big sting works like this: a suspect is led to believe that he is being wooed to join a criminal empire. Eventually, the suspect is taken to meet the organisation's boss - 'Mr Big' - to whom he must detail his past criminal exploits in order to gain admission to the gang. In some scenarios, Mr Big provides the suspect with some details of the crime - in order to demonstrate his criminal omnipotence - and in others, he tells the suspect he can get someone else to take the fall for the crime, but needs details to make it convincing. Police involved in at least two prominent murder cases have used variations of the technique, although the exact number is not clear because other suspects may have lodged guilty pleas. Defence lawyers have long argued that evidence obtained in a Mr Big sting is tainted, because suspects may be exaggerating to impress someone they think is capable of more violence than they are. Or maybe they simply lie in order to get into Mr Big's lucrative and glamorous gang. However, The Supreme Court of Canada recently ruled that such sting operations are legitimate police techniques. The Mr Big operation is so controversial that you might think criminals would have caught on. But apparently they haven't been paying attention. Tomorrow: New York