Enhanced Characterization of the Smell of Death by Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry (GCxGC-TOFMS)

Soon after death, the decay process of mammalian soft tissues begins and leads to the release of cadaveric volatile compounds in the surrounding environment. The study of postmortem decomposition products is an emerging field of study in forensic science. However, a better knowledge of the smell of death and its volatile constituents may have many applications in forensic sciences. Domestic pigs are the most widely used human body analogues in forensic experiments, mainly due to ethical restrictions. Indeed, decomposition trials on human corpses are restricted in many countries worldwide. This article reports on the use of comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS) for thanatochemistry applications. A total of 832 VOCs released by a decaying pig carcass in terrestrial ecosystem, i.e. a forest biotope, were identified by GCxGC-TOFMS. These postmortem compounds belong to many kinds of chemical class, mainly oxygen compounds (alcohols, acids, ketones, aldehydes, esters), sulfur and nitrogen compounds, aromatic compounds such as phenolic molecules and hydrocarbons. The use of GCxGC-TOFMS in study of postmortem volatile compounds instead of conventional GC-MS was successful

Post-mortem volatiles of vertebrate tissue

Volatile emission during vertebrate decay is a complex process that is understood incompletely. It depends on many factors. The main factor is the metabolism of the microbial species present inside and on the vertebrate. In this review, we combine the results from studies on volatile organic compounds (VOCs) detected during this decay process and those on the biochemical formation of VOCs in order to improve our understanding of the decay process. Micro-organisms are the main producers of VOCs, which are by- or end-products of microbial metabolism. Many microbes are already present inside and on a vertebrate, and these can initiate microbial decay. In addition, micro-organisms from the environment colonize the cadaver. The composition of microbial communities is complex, and communities of different species interact with each other in succession. In comparison to the complexity of the decay process, the resulting volatile pattern does show some consistency. Therefore, the possibility of an existence of a time-dependent core volatile pattern, which could be used for applications in areas such as forensics or food science, is discussed. Possible microbial interactions that might alter the process of decay are highlighted

The search for “Fred”: an unusual vertical burial case

This case reports details of a multi-phased, geophysical survey to assist in a cold case search. The Police Service received witness intelligence that had stated an adult male “Fred” had been lured to an isolated area, killed and then buried vertically in wooded hilly terrain 30 years ago in the Midlands, UK. Once the search area was determined, conventional search methods proved unsuccessful; therefore, the Police wished for a non-invasive geophysical investigation to be undertaken to determine if “Fred” could be detected. A multi-phased geophysical approach was conducted, initially using bulk ground conductivity and metal detectors, then follow-up magnetics and GPR survey profiles on EM anomalous areas. A tight grid pattern was used to enhance survey resolution over the reduced target size. Relatively high resolution EM and GPR techniques were determined to be optimal in this rugged wooded terrain and sandy soil site. Resulting geophysical anomalies were identified and the most promising area intrusively investigated, the anomaly was found to be due to a large boulder and tree roots. Study implications suggest careful multi-phase geophysical surveys are best practice and can give confidence in a cold case search. This study yielded a no-body result, thus effectively saving Police time and costs from further investigations