Since the publication of Charles Rosenberg's Trial of the Assassin Guiteau in 1968, the question of criminal insanity has been productively mined by historians of psychiatry. For historians of colonial psychiatry, this has been particularly important. One of the key dilemmas facing colonial psychiatrists was where to draw the line between the normal and abnormal behaviours of colonial subjects; insanity defences raised in the courtroom forced psychiatrists - as expert witnesses - to answer this question, with literally life or death consequences, because behaviour which could be deemed 'normal' was behaviour for which a defendant could be held legally responsible. This paper takes as its focus insanity defences raised in the criminal courts of British mandate Palestine, drawing on newspaper reports, official publications, and archival material to uncover how criminal-legal responsibility was debated, evidenced, and staged by psychiatrists, legal officials, defendants, and their families in this context. While the historiography has been alert to the importance of gender in shaping expectations of 'normal' behaviour and thus the outcome of trials, this paper adopts a wider focus. In their verdicts, psychiatrists and the courts did not - and could not - disentangle categories like race, class, and gender in determining the responsibility of defendants. These debates, moreover, looked beyond the identity of the defendant alone. From the late nineteenth century, the mental responsibility of individual members of a crowd had been hotly debated in European sociology and psychology, and in Palestine, outbreaks of violence involving crowds lent a particular urgency to reflections on the limits of responsibility of individual members of a crowd. If membership of a mob might be taken to constitute a state of temporary insanity, another debate - whether intoxication, by drugs or alcohol, might attenuate mental and therefore criminal-legal responsibility - also played out in the space of the colonial courtroom too. Though these criminal cases forced the staging of these debates, the complexity of these cases and different agendas of participants meant that far from clarifying the lines between normal and abnormal, sane and insane, responsible and irresponsible, the answers produced in each case remained contingent and specific; it was only when colonial officials with no psychiatric background took a step back from these individual cases that more generalised knowledge about the mind of the colonial population could emerge.