"Is self-defence or defence of another a defence available to a charge of obstructing a police officer under s.89(2) of the 1996 Act?"
"(1) Any person who assaults a constable in the execution of his duty, or a person assisting a constable in the execution of his duty, shall be guilty of an offence and liable on summary conviction to imprisonment for a term not exceeding six months or to a fine not exceeding level 5 on the standard scale, or to both. (2) Any person who resists or wilfully obstructs a constable in the execution of his duty, or a person assisting a constable in the execution of his duty, shall be guilty of an offence and liable on summary conviction to imprisonment for a term not exceeding one month or to a fine not exceeding level 3 on the standard scale, or to both..."
"(1) This section applies where in proceedings for an offence— (a) an issue arises as to whether a person charged with the offence ('D') is entitled to rely on a defence within subsection (2), and (b) the question arises whether the degree of force used by D against a person ('V') was reasonable in the circumstances. (2) The defences are— (a) the common law defence of self-defence... (b) the defences provided bysection 3(1) of the Criminal Law Act 1967 ... (use of force in prevention of crime or making arrest). (3) The question whether the degree of force used by D was reasonable in the circumstances is to be decided by reference to the circumstances as D believed them to be, and subsections (4) to (8) also apply in connection with deciding that question. (4) If D claims to have held a particular belief as regards the existence of any circumstances— (a) the reasonableness or otherwise of that belief is relevant to the question whether D genuinely held it; but (b) if it is determined that D did genuinely hold it, D is entitled to rely on it for the purposes of subsection (3), whether or not— (i) it was mistaken, or (ii) (if it was mistaken) the mistake was a reasonable one to have made... (10) In this section... (b) references to self-defence include acting in defence of another person;..."
"We are police officers. Here is my warrant card. What are you calling at houses for?"
"Of course, in the case of a charge of assault under section 51(1) of the Police Act, 1964, as in the case of any charge of assault, the defence or justification - I prefer to call it a justification, because it must always be borne in mind that it is for the prosecution to exclude justification and not for the defendant to establish it - the justification of self-defence is available just as it is in the case of any other assault. That is subject to this, that if the self-defence, in this case self-defence by the two boys against a prior assault such as had been committed, in a technical sense, by the police officers taking hold of an arm of each of these boys, was self-defence against an assault which was justified in law, as, for instance, a lawful arrest, then in law self-defence cannot afford justification for assault in resistance to justified assault by police officers."
"What was done was not done as an integral step in the process of arresting, but was done in order to secure an opportunity, by detaining the boys escape, to put to them or to either of them the question which was regarded as the test question to satisfy the officers whether or not it would be right in the circumstances, and having regard to the answer obtained from that question, if any, to arrest them."
"To what offence is public or private defence an answer?" it is said: "
"Where a police officer is acting lawfully and using only such force as is reasonable in the circumstances in the prevention of crime or in effecting the lawful arrest of offenders or suspected offenders, self-defence against him is not an available defence."
"It is a principle of the common law that a person may use a proportionate degree of force to defend himself, or others, from attack or the threat of imminent attack, or to defend his property or the property of others in the same circumstances..."
"A hundred years later, in the second edition of his Textbook of Criminal Law (1983) Professor Glanville Williams said pithily at p.501 that 'protective force' can be used to ward off unlawful force, to prevent unlawful force, to avoid unlawful detention and to escape from such detention..."
"... Mr Bain then contended that by a parity of reasoning a father who used force to effect the release of his son from custody was justified in so doing if he honestly believed on reasonable grounds that (contrary to the fact) the arrest was unlawful. We do not accept that submission. The law jealously scrutinises all claims to justify the use of force and will not readily recognise new ones. Where a person honestly and reasonably believes that he or his child is in imminent danger o f injury, it would be unjust if he were deprived of the right to use reasonable force by way of defence merely because he had made some genuine mistake of fact. On the other hand, if the child is in police custody and not in imminent danger of injury there is no urgency of the kind which requires an immediate decision and a father who forcibly releases the child does so at his peril. If in fact the arrest proves to be lawful, the father's use of force cannot be justified..."
"... If a person is properly and lawfully arrested, then use of force to free himself is unlawful. But in this case as a matter of law, it is my responsibility to decide matters of law, I direct you that Police Constable Parker had not, in fact, lawfully arrested McKoy at that stage..."
"... It may be respectfully suggested this proposition is too wide. If D, an innocent person, is attacked by the police who mistakenly believe him to be a gunman and the police attack is such that it would be reasonable if D were the gunman, does the law rely deny the right to resist?"
"... If the constable is acting lawfully there is no reason why a person should be deprived of the defence of self-defence if he genuinely believes in the existence of facts which, if true, would make the use of force by him lawful. Thus, if he mistakenly supposes that a person that has just grabbed him from behind is a robber or a thug, he may use the degree of force necessary to repel a robber or a thug, and it matters not that his assailant is in fact a police officer acting in the execution of his duty. This follows from Gladstone Williams... It should not matter that the crime of assaulting a police officer is a crime of strict liability so far as the status of the victim is concerned... because the offence still requires proof of an assault and the defence of self-defence affords the justification which prevents that element of the crime from being made out..."