British Islamic extremist Junead Khan photographed himself grinning in front of an Islamic State-style flag in the safety of his own home.
However, the 25-year-old from Luton showed no emotion as a jury found him guilty of plotting to kill a US serviceman in a "Lee Rigby-style attack".
Above video report by ITV News Reporter Martha Fairlie
Khan faces a life sentence having abused his position as a delivery driver with a pharmaceutical firm to scout US air force bases while planning the chilling bomb and knife attack.
Detectives later found he had exchanged messages online with an IS fighter in Syria calling himself Abu Hussain, describing how we would attack military personnel after faking a road accident.
Prosecutors claimed Hussain was the British-born fanatic Junaid Hussain, who was killed in a US drone strike in the IS stronghold of Raqqa just weeks after his link with the planned UK attack was discovered.
After Khan was arrested in July, police found the pictures on his iPhone of him posing in his bedroom with the IS-style flag, which they later found in his attic.
His computer was also found to contain an al Qaida bomb manual and Amazon searches for a large combat knife.
Though he never made an order he had gone as far as contacting a company to see how quickly they could deliver the Ontario Marine knife.
Khan was found guilty of preparing for an act of terrorism in the UK between May and July 2015 after a six-and-a-half-week trial at London's Kingston Crown Court.
He was also convicted alongside his uncle, Shazib Khan, 23, of preparing to go to Syria to join IS.
Both men had also filmed themselves as they drove around London visiting high profile terror targets in a video they titled "ISIS drives around Westminster".
The pair passed the Houses of Parliament, Downing Street and the Cenotaph in the video, though it was only Junead Khan who was convicted of involvement in the terror plot.
Both men had denied engaging in conduct in preparation of terrorist acts between August 1 2014 and July 15 2015.
Some of the evidence used to convict the pair cannot be revealed for legal reasons.