A missing person is an individual whose whereabouts are unknown and where there is some concern for his or her wellbeing. In the UK, around 250,000 people are reported missing every year, with the majority being children under the age of 18. Despite the fact that missing persons are a social phenomenon which encompasses vast areas of interest, relatively little is known about those who go missing, what happens to them while they are missing, and what can be done to prevent these incidents from occurring. This groundbreaking book brings together for the first time ideas and expertise across this vast subject area into one interconnected publication. It explores the subjects of missing children, missing adults, the investigative process of missing person cases, and the families of missing persons. Those with no prior knowledge or professionals with focused knowledge in some areas will be able to expand their understanding of a variety of topics relevant to this field through detailed chapters which advance our understanding of this complex phenomenon, discuss what is unknown, and suggest the best and most important steps forward to further advance our knowledge.