6 December 2013 Last updated at 10:10 ET
Blackman, 39, has been told he will spend at least 10 years in prison.
It comes after one of the UK’s highest ranking Royal Marines pledged his “full support” for Blackman, saying he had been “tainted” by the “impact of war”.
On Thursday, three judges at the High Court lifted an anonymity order allowing Blackman to be named.
Lieutenant Colonel Simon Chapman, in a letter read to the judge and board at the court martial in Bulford, Wiltshire, described how Blackman’s promising career had been shattered in a “momentary” lapse of judgment.
The trial – during which Blackman was referred to as Marine A – was the first time a member of the British armed forces had faced a murder charge in relation to the conflict in Afghanistan, which began in 2001.
Two other marines were cleared.
This was not an action taken in the heat of battle or immediately after you had been engaged in a firefight”
End Quote Court martial judge
The murder took place after a patrol base in Helmand came under attack from small arms fire from two insurgents.
One of them was seriously injured by gunfire from an Apache helicopter sent to provide air support, and the marines found him in a field.
The incident was inadvertently filmed by one of the cleared marines – known as Marine B – on his helmet-mounted camera. That footage, taken on 15 September 2011, was shown to the court during the two-week trial.
It showed Blackman shooting the Afghan prisoner with a 9mm pistol.
Sentencing Blackman, the judge told him he had disgraced the name of the British armed services and had put troops’ lives at risk by his actions.
“This was not an action taken in the heat of battle or immediately after you had been engaged in a firefight,” he said.
“Nor were you under any immediate threat – the video footage shows that you were in complete control of yourself, standing around for several minutes and not apparently worried that you might be at risk of attack by other insurgents.”
- Royal Marine Sergeant Alexander Blackman given life term at court martial for killing injured insurgent (standard.co.uk)
- Royal Marine Alexander Blackman faces life sentence for Taliban murder (theguardian.com)
- Marine A named as Sgt Alexander Wayne Blackman (telegraph.co.uk)
- Royal Marine Sergeant Alexander Blackman facing life for murdering injured Afghan insurgent (standard.co.uk)
- 10 year minimum for killer Marine (daventryexpress.co.uk)
- Leniency plea for Marine guilty of Afghan murder (itv.com)
- Marine convicted of Afghan insurgent’s murder named (itv.com)
- Marine who murdered Taliban prisoner loses fight to remain anonymous (theguardian.com)
- Breaking News: Leniency plea for Marine murderer (crosbyherald.co.uk)
- Pictures released of marine on patrol that ended in Taliban fighter’s murder (theguardian.com)