Book excerpt: The present manual was prepared to fill a gap in the compendium of available tools for the judiciary and law enforcement agencies and is the result of a consultative process involving a number of reputable individuals, institutions and organizations, who contributed a variety of different perspectives to this cross-cutting issue, all grounded in the same basic principles common to all crime scenes. The manual aims at raising awareness of the importance of good practices in crime scene investigations and the nature and relevance of physical evidence.