26.If prima facie unlawful physical contact is established, the defendant will need to show that the use of force was pursuant to statutory or common law powers or was undertaken in self defence. The ambit of the latter defence was recently considered by the Court of Appeal in Ashley v Chief Constable of Sussex Police56. The Court held that the burden of proving self-defence lies on the defendant and that he is only entitled to be judged on the basis of a mistaken belief as to the circumstances existing at the time in so far as that belief was both honestly and reasonably held. In judging what is reasonable the Court must have regard to all the circumstances of the case, including that action may have to be taken in the heat of the moment.
27.In Sheppard v The Secretary of State for the Home Department57 the Court of Appeal considered the effect in domestic law of cases decided by the ECtHR under article 3 ECHR indicating that where a detainee sustained injuries whilst in police custody, there was an onus on the police to account for how they were sustained, but held the effect of these authorities was not to shift the legal burden of proving the unlawful battery from the claimant to the defendant, rather they were a recognition of the evidential reality that if the defendant was unable to explain convincingly how the injuries occurred, the claimant would usually succeed in discharging the burden of proof.
28.As regards a claim in assault, the claimant must prove that there has been an act by the defendant that causes him reasonably to apprehend an immediate intention by the defendant to commit a battery. There is no need to show that the alleged tortfeasor actually intended to use force, provided the claimant had a reasonable basis for believing this at the time58.
29.If trespass to the person is established, the claimant is entitled to recover for all consequential humiliation, anxiety and distress; it is unnecessary to show loss by
56  EWCA Civ 1085.
57  EWCA Civ 1921.
58 Chief Constable of Thames Valley Police v Hepburn  EWCA Civ 1841.