Gas chromatography (GC) is now a mature and indispensable analytical instrument in investigational forensic science. High sensitivity, selectivity, resolution and speed, good accuracy and precision, wide dynamic concentration range, simple and robust instrument design, and its ability to easily interface with many established and emerging detection systems have made GC the instrument of choice in many facets of investigational forensic science. A continuous influx of new column chemistries, development of high-precision thermal and pneumatic controlling systems, introduction to programmable temperature vaporizer, advancement in control electronics, and the large number of available detection systems have positioned GC in a unique place in forensic analytical laboratories. Although the applications of GC are limited to volatile and semivolatile organic compounds, rapid development in derivatization chemistry, technology, and high-temperature capabilities have made hundreds of new organic compounds with forensic significance amenable to GC and thus extended its horizon.