As part of an investigation into a homicide, the substance was found in a safe in the suspect's house. Since the suspect was known to have connections to South American terrorist and drug-smuggling groups, the substance was submitted to the laboratory as evidence for a drug case. The material was stored in a large stoppered glass test tube. While a small amount of the material was being ground to be made into a potassium bromide pellet for infrared analysis, the sample exploded with the force of a small firecracker. The powder was obviously not a drug. The analysis of the substance used mass spectrometry, infrared and ultraviolet spectrophotometry, energy-dispersive X-ray spectrometry, and gas chromatography. The substance was identified as triacetonetriperoxide (TATP), a heterocyclic 9-membered trimeric peroxide that is formed by the reaction of acetone with hydrogen peroxide in the presence of mineral acids. TATP is a slightly less powerful explosive than TNT. As long as the material is dampened with an organic solvent, it remains fairly stable, but if it is allowed to air dry, it becomes a very shock, temperature, and friction sensitive high explosive that can even be detonated underwater. The major concern in this case is not the identification of this material, but rather the fact that the material was submitted to the laboratory as a drug sample. Better screening procedures are required to ensure that this does not occur again. 5 figures and 5 references