Mohammed Momin Khawaja grew up in the suburbs of Canada's capital, Ottawa, and was a mild-mannered child who enjoyed hockey.
His father, Mahboob Khawaja, is a university professor based in Saudi Arabia, who has published several works on conflict resolution in which he calls for better understanding of Islamic fundamentalism.
A software developer, Mr Khawaja worked in the technical support department of the Canadian Department of Foreign Affairs and had a good knowledge of electronics.
Of Pakistani origin, he became fascinated by radical Islamist politics, and its focus on conflicts in the Muslim world. He kept up to date on events in the Middle East, Pakistan, Afghanistan and Chechnya through the internet.
According to evidence at the Old Bailey trial of seven British men accused of a plot to bomb the UK, two of whom have been found not guilty, Mr Khawaja travelled to Pakistan and met members of a loose network of jihadi sympathisers - men who believed that violence was legitimate.
Enthusiastic
The other jihadis are said to have found Mr Khawaja enthusiastic and useful and welcomed the £1,800 donation he brought with him.
Mohammed Babar, the American-Pakistani who gave evidence against the British men, arranged for Mr Khawaja to attend a military training camp at Malakand in the country's remote North-West Frontier Province in the summer of 2003. The highlight of his visit to the camp was firing a rocket launcher. It was at this camp that relationships were cemented, the Old Bailey heard.
Following the camp, the party broke up and went its separate ways - but some of the Britons who attended returned to the UK intent on building a bomb. Mr Khawaja's alleged role in this plot was to help to build the detonator, the court heard.
It was in February 2004 that Mr Khawaja appeared on the radar of the security services, who, by then, had the British conspirators under surveillance.
When he arrived at Heathrow airport he was met by Omar Khyam, whose car had already been bugged by MI5. He was being followed around the clock by specialist counter-terrorism officers, his every move watched.
One of the surveillance officers told the court they had no idea who the Canadian was, or what his role was in the plot.
But as Khyam drove off in his Suzuki Vitara, the officers listening in heard the Crawley man and the Canadian discuss a remote-controlled device designed to trigger the bomb the men were planning.
Khyam asked Mr Khawaja if he had "the device" and Mr Khawaja replied that he had a picture of it. He described it as a receiver and transmitter with an aerial requiring five volts and that it would work over a distance of up to two kilometres.
Mr Khawaja said the device worked on a frequency which was impossible to intercept in urban areas and added that its circuitry would prevent it being hacked.
"If you have the detonator wires hooked up that will send a charge down the line and whatever you are sending it to," Mr Khawaja told Khyam.
The following day Mr Khawaja and Khyam met at a house in The Hollows, Crawley, with Waheed Mahmood. This was one of the key bugged meetings which gave the security services an idea of what was being planned.
The pair went to an internet cafe where they looked at photographs of detonators that Mr Khawaja had been building at his home in Ottawa. The pictures were being stored securely on a webmail account so they could not be accessed directly from a home computer's drive.
After three days in London, Mr Khawaja was followed back to Heathrow and his details were passed on to the Canadian authorities.
E-mails intercepted
When he arrived in Ottawa the Royal Canadian Mounted Police began monitoring his phone line and e-mails. The Old Bailey heard that in one e-mail he wrote: "Praise the most high, we get the device working."
And in a co-ordinated operation, they arrested Mr Khawaja on 29 March 2004 and he became the first person to be charged under Canada's Anti-Terrorism Act, introduced in December 2001.
His home in Ontario was searched and the Canadian authorities said they found documents and papers sympathetic to violent jihadi courses of action.
They also said they found circuit boards and a home-made radio transmitter with a form of encryption to prevent accidental operation. This, it is alleged, was the remote control detonator for the improvised explosive device.
Mr Khawaja did not appear at the Old Bailey and is due to go on trial in Canada next month.
