R v Blackman [2017] EWCA Crim 190

Facts

• Sergeant Alexander Blackman, a Royal Marine, was convicted of murder for shooting a wounded insurgent in Afghanistan.
• The incident was recorded on Blackman's helmet camera, capturing incriminating statements made during the shooting.
• Blackman's conviction was initially upheld by a military court.

Issues

1. Whether Blackman’s mental state at the time of the killing met the legal criteria for diminished responsibility.
2. Whether combat stress and adjustment disorder could constitute a significant mental impairment affecting criminal responsibility.
3. The application of civilian criminal law standards to actions taken in a combat environment.

Decision

• The Court Martial Appeal Court allowed Blackman’s appeal, substituting the murder conviction with manslaughter on the basis of diminished responsibility.
• The court found that Blackman suffered from adjustment disorder, which significantly impaired his capacity to make rational decisions or control his actions at the time of the killing.
• The decision acknowledged the psychological impact of prolonged combat exposure on judgment and behaviour.

Legal Principles

• Diminished responsibility, as reformed by the Coroners and Justice Act 2009, requires evidence of a mental impairment arising from a recognized medical condition that significantly impairs understanding, reasoning, or self-control.
• The existence of a causal link between mental impairment and the act of killing is necessary to establish diminished responsibility.
• Adjustment disorder resulting from extreme stress, such as prolonged combat service, may constitute a recognized medical condition sufficient for this defense.
• Psychiatric evidence plays an important role in demonstrating how combat environments can impair mental functioning relevant to criminal liability.

Conclusion

The Court Martial Appeal Court in R v Blackman established that adjustment disorder due to combat stress can amount to diminished responsibility, reducing murder to manslaughter where mental impairment significantly affects decision-making and control. This case clarifies the role of psychiatric evidence and acknowledges the specific impact of military service–related mental health conditions in determining criminal responsibility.