Mass spectrometry occupies a prominent role in the historical evolution of the instrumental analysis of forensic evidence. Most forensic evidence submissions are scheduled drugs, and mass spectrometry, combined with gas chromatography, has provided the gold standard in drug identification for decades. In the earliest ‘forensic’ applications in the 1950s and 1960s, mass spectrometry was used to help identify the elemental compositions and structures of natural products/drugs such as the cannabinoids and tropane alkaloids. In the 1970s, mass spectrometry went out of favor for years for the identification of cocaine because mass spectrometry could not provide information about the enantiomeric form(s) of cocaine that were necessary for prosecution around that time. Once the rules for prosecution were clarified, MS, especially in the form of GC-MS, became the gold standard for almost all organic forensic analyses. Reviews of crime labs in the US and abroad in the 1970s showed several interesting results that are still just as true almost 40 years later: 1) that mass spectrometers are among the most desired new pieces of equipment in existing crime labs, 2) that most forensic analyses involve the confirmation of drugs of abuse, and 3) that mass spectrometry is very valuable for forensic toxicology and is an area destined for more growth in the future. Recent advances in high resolution mass spectrometers, in multi collector isotope ratio mass spectrometers, and in ambient pressure sampling provide a hopeful outlook for continued growth and impact of mass spectrometry in legal applications.