Marine Al Blackman appeals against conviction for killing Afghan
Lawyers for a Royal Marine jailed for life for murdering an injured Taliban insurgent in Helmand in 2011 have told a court his conviction should be quashed.
Former Colour Sgt Al Blackman was found guilty at a court martial in December and sentenced to a minimum of 10 years.
Blackman, 39, of Taunton, Somerset, had his appeal against the verdict and sentence heard at the Court Martial Appeal Court in London.
The result is expected after Easter.
Blackman's defence team said they were appealing against his conviction on the grounds that it was unsafe.
This was based on the defence's belief that the military trial system contravenes the European Convention on Human Rights and the possibility that the military panel in the trial might have reached a majority decision.
In their legal argument, Blackman's lawyers compared the Crown Court system, which has a minimum majority of 10 to two, with a military court, where a simple majority of one is accepted.
It was also argued that the sentence handed to Blackman was "manifestly excessive" because aggravating factors were wrongly taken into account, and mitigating factors not given enough weight.
His QC Anthony Berry described a "cocktail of circumstances" that led to him "losing his head" when he shot the wounded Afghan insurgent.
He added that, "despite the fact that this is an extremely unusual case and gives rise to many different reactions from people, including the public", the sentence of 10 years was too long.
At the conclusion of the legal arguments, Lord Chief Justice Lord Thomas said the court would "take time to consider" its decision on the appeal.
This is expected after Easter.
The court martial previously sentenced Blackman to life imprisonment for murder and then had to decide the minimum term he would have to serve before being considered for release on licence.
The judge advocate and seven-man board made up of senior Royal Navy and Royal Marines personnel weighed up aggravating and mitigating factors.
These included the fact that Colour Sgt Blackman - known as Marine A during the case - was of previous good character.
The military court reduced the minimum term from 15 years to 10 years. Blackman was also dismissed from the Royal Marines.
BBC defence correspondent Caroline Wyatt said the court martial itself was controversial.
On social media much of the public supported Blackman, according to our correspondent, saying the case should never have come to court and been dealt with differently. It also divided military opinion.
However, the judges will have to decide the appeal on legal arguments alone.
Video of shooting
The former marine's wife Claire has told the BBC he is "no risk to society" and should be released.
Blackman was five months into a six-month tour of Afghanistan with Plymouth-based 42 Commando when he shot the Afghan - who had been seriously injured in an attack by an Apache helicopter - in the chest at close range with a 9mm pistol.
The court martial heard a recording of Blackman saying after the shooting "there you are. Shuffle off this mortal coil. It's nothing you wouldn't do to us".
He was then heard to say to his comrades: "Obviously this doesn't go anywhere, fellas. I just broke the Geneva Convention."
Sentencing Blackman in December, Judge Advocate General Jeff Blackett told him he had disgraced the name of the British armed services and video of the shooting showed he had not been "under any immediate threat" when he fired.
In fixing the minimum jail term, the judge said the court took into account the effect of the arduous six-month tour upon Blackman but said "thousands of other service personnel have experienced the same or similar stresses" and had not acted in the same way.