Explosion investigators are faced with circumstances which vary from having little more than a notebook, pencil, measuring tape, and a problem, to being in possession of the resources of a highly sophisticated modern laboratory. Simple techniques are detailed for those confronted with the former situation, while the possibilities open to their colleagues are indicated also. Important background information on field and laboratory work dealing with both manufactured and homemade live explosive devices is provided. Specific topics discussed are observation and assessment of damage (the significance of pressures, the phenomenon of fragments and information to be gotten from fragments, craters and ground vibrations, causes of initiation (heat, sparks, chemical effects, etc.), and explosives identification. While some aspects, such as chemical analysis and damage effects, are discussed in some depth, others, such as the hydrodynamic theory of detonation and manufacturing techniques, are only briefly noted. Sections on approaching the scene, analyzing witness statements, using negative evidence, and drawing conclusions contain material of wide application in forensic science. Distant-weight-pressure values are provided in tabular form, and descriptions of spot tests, quantitative analyses, and thin layer chromatography tests are included. A glossary of differences between United Kingdom and U.S. explosive terminology is appended. Over 50 references and an index are provided.