Where the court was not able to conclude that an arresting police officer's actions were unreasonable that court could not find the arrest to have been wrongful.Appeal by the defendant chief constable from the ruling of HH Judge Durman during a trial with a jury that the evidence of the police, taken at its highest, had not established reasonable cause for the arrest of the claimant with the result that judgment was given for the claimant for wrongful arrest in an agreed sum of ?6,000. The claim arose out of the arrest of the claimant by a woman police sergeant following an incident during which a traffic warden had tried to write out a ticket for the claimant's nephew's car. The sergeant gave evidence that the traffic warden had told her that the claimant had tried to knock her note book from her hand. The sergeant considered that there had been a common assault and requested the claimant's name and address. The claimant refused and became agitated and was arrested for failing to provide her details in order to be summoned on suspicion of common assault and for breach of the peace. The police contended that the claimant had been lawfully arrested, under the provisions of s.25 Police and Criminal Evidence Act 1984, on suspicion of having committed the offence of common assault, and to prevent a breach of the peace. The grounds of appeal were that: (i) the judge had erred by ruling that "knocking the note book" from the traffic warden's hand did not amount to a common assault; and (ii) ruling that the issue regarding the existence of a breach of the peace should not be left to the jury. The lawfulness of the arrest turned upon the question of whether, in the terms of s.25(1) of the Act, the officer had "reasonable grounds for suspecting that an assault had been committed or attempted" by the claimant.HELD: (1) The conduct of the claimant relied on by the police involved no questions of injury or possible threat of injury to any member of the public, save, arguably, the arresting police officer herself. No verbal threats were said to have been made. Mere agitation did not involve a breach of the peace. The sergeant did not suggest that she had feared imminent violence to herself or her property nor that there had been any reason or necessity for public alarm. In the circumstances the judge was entitled to take the view that, taking the evidence at its highest, there were no proper grounds established for arrest in relation to a breach of the peace or apprehended breach of the peace. (2) The question to be answered was whether at the time of effecting the arrest of the claimant the sergeant had reasonable grounds for suspecting that she had assaulted, or attempted to assault, the traffic warden. O'Hara v Chief Constable of the Royal Ulster Constabulary (1997) 2 WLR 1 applied. The test was partly subjective, in that the arresting officer must have formed a genuine suspicion that the person being arrested was guilty of an offence, and partly objective, in that there had to be reasonable grounds for forming such a suspicion. (3) If a judge decided to withdraw the issue from the jury, it was essential to properly focus on the issue that fell for decision. That issue required the judge: (a) to concentrate on the officer's state of mind at the time of arrest; and (b) to approach the matter on a broad basis taking into account not only what she had been told by the traffic warden but what she had herself observed. (4) On the assumption which the judge was obliged to make (because he did not leave it to the jury) that the officer was honest in her suspicion, he was in no position to say that such suspicion was not reasonable. The sergeant plainly had reason to think that what had happened to the traffic warden amounted to an assault.Appeal allowed.
 EWCA Civ 397