A guide developed by The Royal College of Pathologists and The Royal College of Paediatrics and Child Health to provide guidelines for the investigation and management of sudden unexpected deaths in infancy and childhood. It supports the work of professionals from multiple agencies—doctors, pathologists, prosecutors, police, emergency services, child welfare staff, among others—in conducting thorough investigations in these cases. The document aims to standardize practices and promote interagency collaboration, fostering an approach that integrates the emotional needs of families, as well as the clinical and legal aspects of the case.