Kenlin v Gardner  2 QB 510;  3 All ER 931
WINN LJ: This is a Case Stated by two justices of the peace for the Metropolitan Area Inner London Juvenile Courts...sitting...as a juvenile court on 22 November 1965, when the appellants, two boys of fourteen, were charged before them with assaulting the respondents, two police officers, in the execution of their duty and were convicted. This is a most unfortunate case which really might better have died down in the teacup in which the storm first began to arise. The respondents were acting in a perfectly proper way, apart from the merest technicality to which it will be necessary subsequently to refer. The appellants were perfectly innocent and engaged in no improper behaviour of any kind. Counsel for the appellants used an expression when addressing the court, which with his permission I will adopt: he said that the whole thing was a clash of misunderstandings-the respondents misunderstood what the appellants were doing, and the appellants misunderstood what the respondents were doing to them. The respondents were in plain clothes, and in all probability not in their best plain clothes. As the justices have found, the appellants though that, so far from being police officers, they were thugs.
It seems that in the middle of the day on a date in October, 1965, the appellants were going to a number of houses in the Stoke Newington area in order to remind members of their school rugby fifteen of the date or place at which a forth-coming match was to be played, a perfectly innocent errand, and they were going together from house to house knocking on the doors. The respondents saw them engaged in that manner, and as the justices thought, became genuinely but erroneously suspicious of the two appellants. Just what they suspected is not expressly found in the Case; maybe they thought that they were going from house to house begging; it may be that they thought that they were going from house to house looking for a door or window which was not secure with a view to breaking in and committing felonies in the house. At any rate, one of the respondents went up to the two appellants, properly acting in a reasonable and correct way, produced his warrant card and showed it to them and said: "We are police officers, here is my warrant card. What are you calling at houses for?" Unfortunately the warrant card in its talc case, one supposes, could not be readily read; whether the appellants did not read quickly, whether they were frightened, or what was the explanation, the fact is that they did not appreciate from the displaying to them of the warrant card that the respondents were police officers, and they were frightened by being so accosted. Neither of them said anything; one of them made away. He tried to run away, whereupon one of the respondents, acting in a sensible, normal and natural way (but unfortunately, in view of the technical point thereby involved) caught hold of him by the left arm, using no violence to him, but merely seeking to hold him from escape, and said: "Now, look, son, we are police officers, what have you been up to?" Then he cautioned him. Immediately the appellant began to struggle violently and punched the respondent several times with one of his arms, in fact the only free one, the right arm, about the chest and body and kicked him about the legs. The other appellant was told by the other officer to stand against the hedge and not to run away; the first appellant, who was, one might say, a stalwart for his rights as a citizen, demanded that his warrant card should be produced by the second respondent. He really could not get at that because of the struggle, and so the other appellant took fright also and started to run away; but he was chased and caught by the right arm, he then turned and struck that respondent with his free arm and tried to kick him; then he went off and ran away home, either to his mother, or more probably to his father to tell him how bravely he had conducted himself. So the struggles went on until one of the appellants, with the help of a passer-by who happened to come along with a motor car, was put into the car. He went on shouting "You're not police officers. Don't let them take me away". He went on in that fashion until he realised that the car was bound for the police station, then he calmed down and everything was quiet. There was no more trouble until they came before the magistrates, who came to the conclusion that the violence shown to the respondents amounted in law to assaults, though only technical assaults; and so after conviction they very sensibly granted each of the boys an absolute discharge on each of the informations. Now this case comes before this court with some tendency to put it forward as a cause célèbre, a state trial-I say that deliberately but without any intention to be insulting to either counsel. In my own view it is nothing of the kind; it is quite a simple and normal case where misunderstandings led to an unfortunate consequence, which need not have involved any prosecution.
The appellants undoubtedly assaulted the respondents: there cannot be any doubt about that, they struck them and kicked them; but the question is whether that was a justifiable or unjustified assault; and that again, as counsel for the appellants agreed, depends entirely on whether the answer of self-defence was available to the appellants in the particular circumstances. In the case of a charge of assault under s 51 of the Police Act 1964, as in the case of any charge of assault, the justification of self-defence is available just as it is in the case of any other assault. I prefer calling it a justification, to calling it a defence, because it is for the prosecution to exclude justification and not for the defendant to establish it. That is subject to this, that if the self-defence, in this case self-defence by the appellants against a prior assault such as had been committed, in a technical sense, by the respondents taking hold of an arm of each of the appellants, 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 a police officer. So one comes back to the question in the end, in the ultimate analysis: was the respondent entitled in law to take hold of the first appellant by the arm, was he justified in committing that technical assault by the exercise of any power which he as a police constable possessed in the precise circumstances prevailing at that exact moment? The same question arises in regard to the other respondent and the second appellant a little later on. I regret, that I feel myself compelled to answer that question in the negative. This respondent might or might not in the particular circumstances have possessed a power to arrest the appellants. I leave that question open, saying no more than that I feel some doubt whether he would have had a power of arrest; but on the assumption that he had a power to arrest, it is to my mind perfectly plain that neither of the respondents purported to arrest either of the appellants. 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 appellants from escape, to put to them or to either of them the question which was regarded as the test question to satisfy the respondents 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.
I regret to say that I think that there was a technical assault by each of the respondents. From which it follows that the justification of self-defence exerted or exercised by the appellants is not negatived by any justifiable character of the initial assault. It is plain in my own view that it was within the province of self-defence. The court is not asked to send back this case to the justices for them to decide just what was the ambit of the self-defence permissible in the circumstances, what were the reasonable or unreasonable features of the conduct of the appellants in seeking to defend themselves. It suffices to say that the self-defence justification was available to the appellants, and that it is not shown on the facts found by the justices that there was an excess of that liberty.
The justices have asked certain questions...rather in the nature of an examination paper. It is not necessary to give any detailed answers to them, but I will give the answers in case they themselves want to know them, as they have consulted the court. The answer to question (i) is-yes as to any assault unless the assault resisted was itself justifiable. The answer to questions (ii) and (iii) is that knowledge that the man attacked is a police officer is unnecessary, but a genuine mistake of fact as to the character of the person concerned, eg, genuine and reasonable belief that he was a thug and not a police officer, would be highly material in judging the scope of reasonableness and the degree of force falling within the liberty or justification of self-defence. Question (iv), the question as to what is the difference between assault and "resists", does not really need an answer. The two words have quite different meanings. "Resists" does not necessarily involve an assault. For these reasons I think that this appeal should be allowed and this conviction quashed.