Using the example of a multiple filicide, we review challenges facing medical experts who examine unexplained multiple infant deaths in the context of a criminal trial. These include the complex and contradictory nature of evidence, the difficulty in achieving medical consensus to explain multiple sudden deaths, errors and vulnerabilities associated with clinical judgment, and pressure from legal practitioners to achieve a favorable result. In Folbigg, evidentiary rules regarding coincidence and tendency appear to have skewed expert opinion, and consequently, fact-finder reasoning. A central problem was the limitation of medicine to clearly account for each of the four deaths, let alone all four. Medical experts were required to identify similar cases in their experience or concede that multiple sudden infant deaths could be accounted for only by suspicious circumstances. Empirical research on decision-making under conditions of complexity, uncertainty, and adverse outcomes reveals the potential for judgmental errors. The propensity for error increases when experts testify in court and transform probabilistic medical judgments into statements of certainty.