A. Establishing Priorities
When a bombing case is received by a forensic laboratory, the following questions are essential to establish investigative priorities:
- Fatality Assessment: Are there fatalities involved in the bombing incident?
- Serial Bombing Consideration: Is the case potentially part of a series of bombings, necessitating urgent action to prevent future incidents?
- Suspect Corroboration: Have investigators identified a suspect? If so, lab priorities might shift towards corroborating evidence to confirm or exclude the suspect.
- Search Warrant Support: Does the lab need to provide information for probable cause to issue a search warrant? The lab findings can determine the scope of the warrant, such as checking for explosive residues or searching for specific tools used in the bomb’s construction.
- Demographic Profiling: Is the device typical of those used by juveniles, or is it something recently discussed on computer bulletin boards?
- Criminal Affiliation Analysis: Is the bomb of a type commonly used by organized crime groups?
- Traceability of Components: Are any of the bomb components uniquely traceable, which can help in tracing the origin of the device?
B. Investigative Evidence
A variety of investigative information can be obtained from the laboratory analysis of explosive devices:
- Sophistication level of the bomb maker: Analyzing the complexity of the device to assess the skill and expertise of the individual who constructed the bomb.
- Source for the design concepts of the device: Determining whether the design is copied from available literature or indicates military knowledge or training.
- Similarity to other devices: Utilizing the ATF’s EXIS (Explosive Incidents System) database, which contains details on domestic bombings, to compare device components, targets, motives, etc., with over 52780 incidents logged.
- Sources for the individual components of the device: Identifying the origins of the components, often through laboratory contacts with industries such as explosives manufacturers, electronics stores, model rocketry suppliers, pipe and fittings suppliers, and manufacturers of low explosives like black and smokeless powder, adhesive tapes, batteries, etc.
- Nature of the explosive: Assessing whether the explosive is commercial or improvised, identifying the knowledge source for improvised devices, tracing where the necessary chemicals could be acquired, and the level of training or knowledge required for manufacturing the explosive.
References: Forensic Investigation of Explosions By David R. Gaskel