Book excerpt: The evidence discovered at underwater crime scenes must be handled with the same attention to proper chain of custody procedures as with any other type of investigation. Improper handling of these scenes can lead to evidence being lost, unrecognizable, destroyed, contaminated, or rendered inadmissible at the time of trial. Updated and expanded, Underwater Forensic Investigation, Second Edition presents a comprehensive approach to the processing of an underwater crime scene and the steps necessary to conduct the operation. The book summarizes the history, physics, and laws applicable to underwater investigations and includes topics such as team formation, roles, deployment, and accountability. Explaining procedures that can make a true difference in the final outcome of water-related incidents, the author also debunks myths associated with submerged evidence. This second edition contains several new chapters on photography, contaminated sites, preservation of evidence, and release of the crime scene, and includes expanded information on death investigation and organizing the dive team. Nearly 100 color illustrations supplement the text. The science of water-related investigations is still in its infancy, and hence, the field needs accurate and useful sources of education. This text will assist law enforcement professionals and those in other areas of public safety in gaining the knowledge that has historically been lacking. The incorporation of the procedures presented will enable those tasked with working these scenes to develop a greater degree of professionalism, objectivity, thoroughness, and accuracy relating to the investigation of water-related incidents—increasing the chance for successful resolution of these difficult cases.