"The principal purpose of this Guide is to provide an investigative outline of the tasks that should be considered at every explosion scene. They will ensure that proper procedures are used to locate, identify, collect, and preserve valuable evidence so that it can be examined to produce the most useful and effective information--best practices. This Guide was designed to apply to explosion and bombing scene investigations, from highly complex and visible cases, such as the bombing of the Alfred P. Murrah Federal Building in Oklahoma City, to those that attract less attention and fewer resources but may be just as complex for the investigator. Any guide addressing investigative procedures must ensure that each contributor of evidence to the forensic laboratory system is served by the guide and that quality examinations will be rendered. Consistent collection of quality evidence in bombing cases will result in more successful investigations and prosecutions of bombing cases. While this Guide can be useful to agencies in developing their own procedures, the procedures included here may not be deemed applicable in every circumstance or jurisdiction, nor are they intended to be all-inclusive. The most common types of explosive/incendiary devices encountered by fire service and law enforcement personnel in the United States are traditionally pipe bombs, Molotov cocktails, and other improvised explosive/incendiary devices. The most common explosive materials used in these devices are flammable liquids and black and smokeless powder. This guide contains: a principle citing the rationale for performing the task; a procedure for performing the task; and a summary outlining the principle and procedure."