Whether Canning, 37, set out deliberately to seduce Audrey Lamb, 60, - real name Ethel Lamb - with the intention of exploiting her loneliness following the end of a 22-year relationship remains unclear. What is more certain is that she became devoted to him, even when she realised he was involved in the IRA bombing campaign in London during late 1991 and early 1992.
The curtains of Lamb's semi- detached home in a cul-de-sac in Northolt hid Canning's storehouse of arms and explosives. He used the house to make and store bombs and incendiaries and as a rendezvous point for other IRA terrorists. He built a secret bunker in the garden to store Kalashnikov rifles.
The trial was told that Lamb gradually learnt of his role as a terrorist. Ann Curnow QC, who defended her, said: 'He waited until she was emotionally hooked, totally dependent on his continuing presence and his love. And then he started these months of degradation and dragging down . . . he used her mercilessly.' Canning threatened the IRA would blow her up if she told anyone.
Canning's methods of operation were different from other IRA terrorists identified by police during the current campaign. Typically, these are teams of two or three younger, harder men, using a variety of rented addresses, second-hand cars, aliases and false documentation. Rarely staying in one place, they never attempt to devise 'cover'.
He met Lamb when a regular at the Adam and Eve public house in Hayes; after moving into her home he would go shopping, play golf, do odd-jobs around the house. There were lengthy drinking sessions at the Adam and Eve.
Lamb supported him with money from the sale of the greengrocery business she had run with her former partner. She bought him a car, there was talk of marriage and, at a party in the pub, they swapped rings. How much of this was genuine on Canning's part can only be surmised. Her friends accepted him, happy she no longer went to the launderette every day for company.
Detectives believe Canning, Scottish-born but raised in Northern Ireland where he has five children, belongs to the 'second tier' of IRA terrorists who live as ordinary citizens but plan or carry out some bombings and give logistic support to other teams, perhaps those charged with more important missions.
He also acted as storekeeper: the Kalashnikov used to shoot Sir Peter Terry, the former Governor General of Gibraltar, in September 1990 was among those he was guarding, although the trial was told there was no suggestion that he was the man who fired it.
Canning's fingerprints were found on the bomb defused outside the Beck Theatre in Hayes in June 1991, where the band of the Blues and Royals were due to play that night, suggesting that Canning was involved in the making of the bomb, at the very least.
After arrest, Lamb confessed all. She said he supplied the firebombs placed in shops in the West End and the Brent Cross Shopping Centre in north London in December 1991, and also a firebomb in the National Gallery the following day.
Canning was also alleged to have been deeply involved in the attacks on trains and railway stations during the winter of 1991-92. These included a bomb left near Clapham Junction, which may have been placed by a man named Martin, and one at London Bridge station in February, planted by a man called Gerry.
According to Lamb, he was responsible for two small bombs in the Whitehall area: a bomb in a briefcase in Whitehall Place, near Downing Street, on 10 January last year which exploded without injury and another in a telephone kiosk in Parliament Street on 11 February, which was defused.
There is no suggestion that Canning was involved in the massive bombs which shook the City of London and Staples Corner in London on 10 April - the IRA's welcome to the new government. But Canning realised the heat was on and in a panic began transferring weapons and explosives to a rented lock-up garage.
Detectives watched his movements and entered the garage to discover exactly what had been at Islip Gardens. They decided it was time to move in and Canning and Lamb were arrested after their final evening together, drinking at the Adam and Eve.