A leading modern authority on omissions in criminal law. The House of Lords held that when a defendant inadvertently creates a dangerous situation and subsequently becomes aware of it, he is under a legal responsibility to take reasonable steps to prevent or reduce the risk. His failure to act, if accompanied by the required mens rea, can constitute the actus reus. This case forms the foundation of the “created danger” omission duty. 

Miller, a vagrant, slept in an empty house. While lying on a mattress, smoking, he fell asleep. His lit cigarette ignited the mattress. When he awoke and saw it smouldering, he did nothing to extinguish it and simply moved to another room. The fire spread and caused £800 worth of damage to the house. 

Whether the actus reus of arson is present where a defendant accidentally starts a fire but, upon becoming aware of it, recklessly fails to take steps to extinguish it or prevent damage. 

Appeal dismissed. The House confirmed that the offence was made out. Once Miller realised that his earlier act had created a risk of property damage, he had a responsibility to take reasonable steps to avert or reduce the risk. His failure to do so, coupled with recklessness, satisfied the requirements of arson under s 1(1) and (3) Criminal Damage Act 1971. 

Where a defendant creates a dangerous situation, even accidentally, and later becomes aware of the danger, his subsequent omission to take reasonable steps to prevent or minimise harm can form the actus reus. If, at that point, he is reckless as to the risk of damage, either by consciously taking the risk or by failing to consider an obvious risk, liability under s 1(1) arises.