It’s not possible to predict horrific acts, writes Stephen Smith while Bill Nightingale and Sarah James draw attention to the underfunding of mental health services and other public services

Gaby Hinsliff (Axel Rudakubana walked a long path to murder. At what point could he have been stopped?, 24 January) and your editorial (23 January) ask the question that arises when somebody commits an act that causes us deep distress: “What can we do to prevent this from happening again?” The realistic answer, sadly, is “nothing”, because such obscene acts are not manageable by social care, policing or state intervention. There are very dark places lurking in some human beings, and there are no policies or interventions that will eradicate them. Fortunately, such acts are extremely rare.

The law cannot permit “preventive detention”, or punishment before the crime. A large number of people are walking around with sociopathic, psychopathic and disturbing personality characteristics. Until they commit a crime, they cannot have their liberties curtailed. An inquiry might help, though there is a risk that, as ever in moral panics, socially harmful increases in the power of state agencies will penalise significant numbers of people who would do no harm.