Abstract

Justice systems are sometimes called upon to evaluate cases in which health care professionals are suspected of harming or killing their patients. These cases are difficult to evaluate since investigators need to consider whether the deaths that prompted the investigation could plausibly have occurred for reasons other than homicide, in addition to considering whether, if homicide was indeed the cause, the person under suspicion is responsible. Suspicions about medical murder sometimes arise due to a surprising or unexpected series of events, such as an apparently unusual number of deaths among patients under the care of a particular healthcare worker. But also, a single unexpected event might trigger suspicion about a particular healthcare worker, and this might then lead to investigation of events which happened when he/she was thought to be present. We show that an apparently striking association between a healthcare’s presence and a high rate of deaths in a hospital ward can easily be completely spurious. There is a statistical challenge of distinguishing event clusters that arise from criminal acts from those that arise coincidentally from other causes. The talk will be based on the RSS report 2022 Health care serial killer or co-incidence? and Dotto, Gill, Mortera (2022) Statistical analyses in the case of an Italian nurse accused of murdering patients.