The published summary of bombing incidents in 1995 was provided, and the committee heard about how information was gathered through voluntary reporting by local law enforcement personnel. Special Agent Carl noted that smokeless and black powders were used in a significant percentage of the reported improvised explosive devices (roughly one-third), and therefore it was reasonable to consider tagging such powders. He wondered how specific the information from taggants would be, as more specific information is more helpful for obtaining convictions. He said that, without taggants, technicians already are able to identify the brand of powder used in an incident based on unburned powder found at the scene. Currently, the FBI does not have an official position on the use of taggants or on how much information such taggants should contain. Special Agent Carl also expressed concerns about cross-contamination and difficulties in taggant retrieval, as often data collection at bombing scenes is performed by local law enforcement personnel, who do not have access to expensive equipment or extensive training in trace-evidence preservation. The FBI would prefer improved detection technology, as finding and disarming devices before they explode prevents injuries, deaths, and property damage, and preserves evidence. However, bomb squads would always err on the side of caution, so positive or negative signals from markers would not necessarily change the response protocols.
Roger E. Broadbent, Virginia State Police,3 works with bomb squads and crime scene technicians. The state police support local and federal agencies as needed in both preblast and postblast investigations. He indicated that, as he understood it, taggants could only provide information about the manufacturer of the powder or the date it was produced. Such information would provide limited circumstantial evidence; more useful data could be collected from other parts of the explosive device, such as the pipe, packaging, wires, and so forth. If more detailed information about the powder were to be available, an extensive record-keeping system would be needed, and the last piece of information would depend on the purchaser's willingness to identify himself honestly at the point of sale. Mr. Broadbent expressed concerns about contamination, as a great deal of ammunition is fired legally and would introduce taggants into the environment. He also was worried that if taggants were excluded from certain types of ammunition, such as those used by the police, a black market would develop. Currently, based on his experience with bombing investigations, he believes that most perpetrators purchase commercial powders off the shelf; they do not steal the powders, and they do not make their own.
Anthony Cantu and John Hudson, U.S. Secret Service,4 spoke about the surveying of buildings for explosive devices in order to ensure the safety of the Presi-