‘Drugs: identifying illicit substances’ provides an overview of the range and complexity of forensic drug examination. Without accurate identification of suspected drugs, the law cannot be enforced. Drug examinations begins with visual identification of samples. Presumptive testing follows, which acts as a screening mechanism to prevent unnecessary analysis of clean samples. More detailed analysis, such as chromatography, can then be carried out to confirm the presence and type of drugs. Forensic evidence can also help in trafficking investigations. Physical fit evidence, such as complementary rips and patterns on pieces of paper wrapping, can identify if drug samples have come from the same source.