The case of McCarthy v Chief Constable of Merseyside Police [2016] EWCA Civ 1257 provides an interesting analysis of the tort of battery, trespass ab initio and use of reasonable force relating to use of a taser in a policing context. The Court of Appeal judgments provide clear recognition of the difficulties and realities faced by police officers in the context of fast moving, violent incidents in which fine judgments are difficult and provide important guidance as to the correct factual and legal approach in such cases.