The chemical processes of human cadaver decomposition are complex and not well understood. The study of decomposition chemistry aims to elucidate the postmortem processes, particularly relating to the production of volatile organic compounds (VOCs) throughout the various decomposition stages. The use of thermal desorption coupled with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (TD-GC×GC-TOFMS) has allowed for the VOC profile of decomposition odor above pig carcasses (human analogues) to be determined. An enhanced data-processing approach combining Fisher ratio calculations with principal component analysis assisted in the identification of the major classes of compounds that contribute to the VOC profile and their variation across decomposition stages. Detection and profiling of these VOCs is valuable for understanding the mechanisms by which human-remains detection (HRD) dogs locate victims in mass disasters and forensic investigations.