**Background:** The review addresses the complex process of human decomposition and the volatile organic compounds (VOCs) that constitute 'odor mortis.' Understanding VOC profiles is crucial for forensic medicine, particularly for estimating postmortem interval (PMI), determining cause of death, and training human remains detection (HRD) dogs. The paper systematically analyzes current knowledge on VOCs emitted from decomposing material, considering intrinsic and extrinsic factors that influence their profile.
**Methods:** This is a narrative review that synthesizes findings from multiple studies on decomposition VOCs. The authors categorize the decomposition process into five stages (fresh, bloated, active, advanced, dry) and discuss the biochemical changes and VOC emissions at each stage. They review studies using human cadavers and animal models (primarily pigs), as well as research on factors affecting VOC profiles, including temperature, soil type, water environment, biotope, thanatomicrobiome, and insect activity. The review also covers analytical techniques such as headspace solid-phase microextraction (HS-SPME), sorbent tubes, and two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC-TOFMS).
**Key Results:** The review highlights that VOC profiles are highly variable and influenced by numerous factors. Temperature is a major factor: a study at an average outdoor temperature of 24.1°C detected nearly all chemical classes (e.g., 172 aliphatics, 25 aromatics, 19 nitrogen compounds), while winter studies found fewer VOCs (116 vs. 256 in summer). Soil type affects VOC release; clay soil may inhibit odor due to reduced permeability, while moist and acidic soils enhance VOC detection. Submerged remains produce different profiles than surface-deposited ones (41 vs. 70 VOCs in one study). The thanatomicrobiome plays a critical role: bacterial families such as Tissierellaceae, Erysipelotrichaceae, and Xanthomonadaceae are significantly correlated with indole and phenol emissions. Insect activity also modifies VOC profiles; for example, colonized carcasses emit more acids and aldehydes, while uncolonized ones emit more sulfur compounds. HRD dogs demonstrate high sensitivity and specificity (e.g., 99.8% success in identifying grave soil samples, 96.8% accuracy in recognizing soil solutions). However, differences between human and pig decomposition are noted: pigs decompose faster (active decay in 6–8 days vs. 14–21 days for humans) and exhibit unique VOCs (e.g., diethyl disulfide, pyridine). Human-specific VOCs include esters like 3-methyl butyl pentanoate and 3-methyl butyl 3-methyl butanoate.
**Clinical Implications:** The review underscores the potential of VOC analysis to complement standard autopsy methods for PMI estimation and death investigation. Identifying human-specific biomarkers could improve HRD dog training and reduce false positives. Portable VOC detectors and geophysical methods may enhance field recovery of buried remains. However, standardization of VOC profiles, larger sample sizes, and longer collection timelines are needed. The use of human cadavers is recommended over animal models for accurate PMI estimation, though pigs remain useful for baseline data. Future research should focus on the VOC profiles of individual tissues, organs, and body fluids, as well as the influence of entomological diversity and environmental conditions.