It was “feeble”. It was “very unsatisfactory”. It was, in short, “terrible”. If you wish to annoy a statistician, ask them about the trial of Lucy Letby, a British nurse. Statisticians will, typically, take no view whatsoever on the guilt or otherwise of Letby, who in August last year was found guilty of murdering seven very young babies in a hospital near Liverpool between 2015 and 2016, and given 15 life sentences without the chance of parole.

They do, however, have very strong views on the way her trial – which relied in part on analysis of hospital rotas – proceeded. “The conviction is unsafe,” says Peter Green, a maths professor at Bristol University. It was the kind of case “that leaves a bad taste in the mouth”, says Philip Dawid, a statistics professor at Cambridge University. Statisticians were “shocked”, another eminent professor explains, by the way the trial weighed the probability of seemingly extraordinary events.

The Economist