TATP

TATP — short for triacetone triperoxide — is a homemade, peroxide-based explosive that is treated as a central item of evidence in international terrorism cases and in investigations concerning preparation of terrorist acts. The concept belongs to international criminal and security law and is not tied to any single national legal system.

Chemically, the substance is formed from acetone and hydrogen peroxide under acid catalysis, and it is characterised by its white, crystalline appearance. TATP is extremely sensitive to heat, shock, friction and static electricity, which makes it particularly dangerous both during manufacture and in storage. This instability means that even minor disturbances can trigger a detonation.

In a legal context, TATP typically appears as technical evidence in cases concerning preparation of terrorism, unlawful manufacture of explosives or possession of explosive substances. Discovery of the substance, or of the chemical precursors used to produce it, can form the basis for charges and indictment under national laws implementing international conventions on terrorism and explosives.

TATP has featured in the investigation of several terrorist attacks internationally, including attacks in Europe in the 2000s and 2010s. The availability of the substance — since the precursors can be purchased legally in many countries — has made it a preferred choice in circles planning acts of terrorism without access to conventional military explosives.

In cases such as the one against Natascha Colding-Olsen, the term TATP is used as the designation of the specific explosive substance forming part of the indictment or of the investigation's technical findings — not as a legal title or an institutional abbreviation. Detection of TATP through forensic analysis is therefore a weighty piece of circumstantial evidence in court.