A highly-experienced Royal Marine convicted of murdering an injured Afghan insurgent should be shown leniency due to the "exceptional circumstances" of the case, a court martial heard today.
Sergeant Alexander Blackman, 39, who has 15 years service, faces life imprisonment after executing the man in "cold blood" in Helmand Province in 2011.
But a judge and court martial board have been urged to pass the shortest sentence possible to give Blackman "a real anticipation of release".
The military court in Bulford, Wiltshire, heard that Blackman - described as a man with a "strong sense of professionalism" - has been awarded numerous medals during his career.
He was described as a man who has "loyally served his Queen and country" through six tours of duty, including Northern Ireland, Iraq and Afghanistan.
Representing Blackman, Anthony Berry QC told Judge Advocate General Jeff Blackett and the board that reports on his client by superiors showed his professionalism .
He said: "The sentence should be so short that he can have a real anticipation of release within not a distant future.
"That is because of the genuinely exceptional nature of the circumstances within this case, the unique circumstances of this case that will allow the court to take this course.
"If one looks at these reports, going back 15 years or so to when he was a recruit, it is perfectly clear from them that from a very early stage indeed he showed capacity for leadership.
"You can see how that progress occurred."
Mr Berry said a report from August last year, carried out days before Sgt Blackman was arrested for murdering the Afghan insurgent, described him as a "strong team player" with "heaps of potential".
A further report, from this year, praised Sgt Blackman's "tremendous professional knowledge and experience", Mr Berry told the court.
He went on to describe the "exceptional circumstances" in which Blackman's shooting of the insurgent - filmed on the headcam of a comrade - took place.
"The marines, as the elite troops, were inevitably put in a forward position. They manifested the front line of allied forces in that area, so that the Taliban could never feel comfortable in an area that they sought to overrun," Mr Berry said.
"They were really lures for the Taliban, while at the same time they were required to go out and so far as they could, win hearts and minds of the local population.
"The responsibility of him, a 39-year-old sergeant with a troop of 15 or so much younger men, was of course immense and the responsibility he felt for their welfare is perhaps the most important and significant feature which underlays the motives and actions of Sgt Blackman when it came to particular moments and, of course, the crucial moment in this case."
Concluding his address to the court, Mr Berry said: "I urge you to be very lenient on this occasion."
The sentence is not due to be delivered until this afternoon.