Where a claimant could show that a tort had been committed at a time when an off-duty officer was apparently acting in his capacity as a constable, the Chief Constable of Police was vicariously liable for any violent acts that the officer had committed.Claimant's ('W') appeal against a decision of HH Judge Mackay at Liverpool County Court that an off-duty policeman, D, had not been acting in his capacity as policeman and that the Chief Constable of Merseyside Police could not therefore be held vicariously liable for D's assault on W. D, an off-duty policeman, had borrowed a marked police van without permission to help his girlfriend move house. At the removal house a sixteen-year-old boy, W, appeared to be rummaging through D's girlfriend's belongings. The incident ended with W being manhandled into the police van by D before being released. W's account was that D had made an unprovoked attack on him and had assaulted him in the police van. That evening W lodged a formal complaint with the local police station. W (through his father) then brought proceedings against the Chief Constable of the Merseyside force under s.88 Police Act 1996 which stated that the Chief Constable was vicariously liable out of the police fund in respect of torts committed by constables under his direction and control in the performance of their functions. D was charged and acquitted. After the criminal proceedings, trial of a preliminary issue was ordered in the civil hearing to determine whether the defendant had been vicariously liable for D's actions. It was held that the assault on W had nothing to do with D being a police officer and that W could not therefore recover damages from the police fund for the assault and imprisonment that he had suffered. W appealed.HELD: Actions were frequently brought against chief constables in respect of the acts of police officers amounting to intentional torts. The powers of a police officer were conferred on him by law, by virtue of his office, so there was no necessity for any authorisation given by his superiors. That authority gave the constable ample powers, and in practice the liability of a chief constable for wilful acts by police officers was more extensive than the vicarious liability of an employer but was not without limit. (Winfield & Jolowicz 16th Ed para 20-14). To establish liability the claimant would have to show more than the mere fact that the tortfeasor had been a police officer. He would have to show that the alleged tort had been committed at the time when the police officer had been acting in his capacity as a constable. From the moment D had started to physically challenge W he was apparently exercising his authority as a constable. He had confirmed to, and W had understood, that he was a police officer. When D had taken hold of W, thrown him down the stairs, assaulted and locked him in the police van saying that he was taking him to the police station, he had been acting as a constable, albeit one who had been behaving very badly. In the circumstances, it was fair that W should recover damages for the assault, injuries caused, and for the time when he had been forcibly confined in the van.Appeal allowed. Previous order quashed. Judgment for claimant on preliminary issue.
 EWCA Civ 111