In the early hours of 26 March 2017 the Appellant, Mr Corey Dixon, was spotted by three Police Officers in an unmarked vehicle whilst he was cycling. The Officers believed that Mr Dixon fitted the description of a suspect who was said to be carrying drugs or weapons in the area, and he was therefore asked to stop, but refused to do so.
PC Haroon then took hold of Mr Dixon's arm and in doing so was not exercising his powers of arrest or stop and search. A struggle then followed between Mr Dixon and two of the Officers, before PC Dolling then intervened as he believed that Mr Dixon was reaching for a weapon. PC Dolling was then bitten on the arm by Mr Dixon.
The Appellant was charged with assaulting all three Police Officers in the execution of their duty under Section 89(1) of the Police Act 1996. He was acquitted for the offences against PCs Haroon and Bailey, as it was held by the Magistrates' Court that the Officers had been acting unlawfully when attempting to detain Mr Dixon, and who was therefore entitled to use reasonable force to desist arrest. He was however convicted for the offence against PC Dolling.
Mr Dixon appealed against the Court's decision that PC Dolling had been acting in the execution of his duty. However, the Crown Court held that whilst the other Officers had been acting unlawfully, PC Dolling was acting in the execution of his duty by trying to prevent his fellow Officers from being unlawfully assaulted.
The High Court was faced with the question of whether PC Dolling had in fact been acting in the execution of his duty, even though his colleagues had conducted an unlawful arrest.
The two cases of Cumberbatch v Crown Prosecution Service; Ali v Director of Public Prosecutions  were discussed during the proceedings and, in the High Court's decision to dismiss the Appeal, the two cases were distinguished from Mr Dixon's case.
In Cumberbatch, the Police Officers who assisted their colleague during an unlawful arrest were held not to be acting in the execution of their duty. However, the Defendant in Cumberbatch was not held to be acting (or threatening to act) unlawfully – her response was reasonable, unlike Mr Dixon whose act of biting PC Dolling constituted an assault and also unreasonable force to resist an unlawful detention.
The case of Ali was also distinguished on the basis that the Police Officers who assisted in an unlawful arrest did not have grounds to believe that the Defendant would exercise unreasonable force, unlike PC Dolling who had a reasonable belief that Mr Dixon was intending to use excessive force via a weapon.
The Court held therefore that there was a justification for PC Dolling's intervention, that he was acting in the execution of his duty and the consequently Appeal was dismissed.
The case is an important decision when considering situations where Police Officers have used force unlawfully against a member of the public, whose behaviour then escalates unreasonably. The fact that the initial use of force by Officers was unlawful did not mean that every action that followed was unlawful. In this case while Mr Dixon was entitled to defend his liberty, he was not entitled to use unreasonable force in doing so. When he used unreasonable force, by biting PC Dolling in the arm, he committed an assault.The High Court noted that the case illustrates the fact that problems may arise in identifying whether an officer is acting in the execution of his duty. The court stated " ……prosecutors should consider making an alternative charge of common assault when they have reason to think that there may be an issue as to whether a police constable was acting in the execution of his duty but that the defendant may nevertheless be guilty of a common assault by reason of having used unjustified force." It was noted that magistrates at a summary trial generally have no power to find an accused not guilty as charged but guilty of a lesser offence. This means that a finding that a constable was not acting in the execution of his duty when assaulted by the accused leads to an acquittal if the only offence charged is an offence under section 89(1) of the Police Act 1996.