This editorial explores the way in which mental health investigations are developing in England and in particular those involving a homicide. A move away from traditional panel inquiries and towards investigations using root cause analysis (RCA) is aimed at shifting the focus from individual blame to identifying system failure. Thus it is envisaged by policy makers that the RCA approach will offer greater learning opportunities for mental health services. The key difficulties associated with panel inquiries are highlighted before describing the intended benefits of the RCA approach. Finally, five key areas where systematic research can support the development of this approach are suggested.