This paper explores the advances made in identifying trace amounts of volatile organic compounds (VOCs) that originate from forensic specimens, such as drugs, explosives, live human scent and the scent of death, as well as the probative value for detecting such odours. The ability to locate and identify the VOCs liberated from or left by forensic substances is of increasing importance to criminal investigations as it can indicate the presence of contraband and/or associate an individual to a particular location or object. Although instruments have improved significantly in recent decades—with sensitivities now rivalling that of biological detectors—it is widely recognized that canines are generally still more superior for the detection of odourants due to their speed, versatility, ruggedness and discriminating power. Through advancements in the detection of VOCs, as well as increased standardization efforts for instruments and canines, the reliability of odour as evidence has continuously improved and is likely to continue to do so. Moreover, several legal cases in which this novel form of evidence has been accepted into US courts of law are discussed. As the development and implementation of best practice guidelines for canines and instruments increase, their reliability in detecting VOCs of interest should continue to improve, expanding the use of odour as an acceptable form of forensic evidence.

a b s t r a c tHexamethylene triperoxide diamine (HMTD) is a homemade peroxide explosive that has become of concern to homeland security due to the ease of synthesis and commercial availability of the materials required for its synthesis. Detection is a challenge because of its exceedingly low vapor pressure and high thermal lability. Though molecular HMTD vapor is essentially undetectable under most circumstances, HTMD is known to degrade under ambient conditions, producing volatile products that could aid in detection. This work studies the evolution of these volatile organic compounds over time and across a number of variables including synthesis method, precursors, storage time, and storage environment. The composition and quantity of these volatiles were compared across these variables. Analysis of the headspace of bulk HMTD was carried out using solid phase microextraction (SPME) with gas chromatography/mass spectrometry (GC/MS). Decomposition was also monitored by gravimetric analysis. Results herein reveal that formic acid is the most abundant decomposition product while formaldehyde is the most commonly detected across all variables. Synthesis method carried the greatest overall effect on decomposition rate and vapor profile composition.Published by Elsevier B.V.

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Detection of canines are well-known to be valuable in the location of contraband, such as explosives or narcotics. More recently, canines have been trained and utilized in the detection of concealed mass storage devices that might contain evidence of illegal activity such as child pornography. To lay the analytical foundation for this detection work, research was carried out to determine the volatile organic compounds associated with mass storage devices (MSD) that could be used by trained canines for detection. Headspace analysis of a variety of electronic devices was performed using solid phase microextraction (SPME) with gas chromatography/mass spectrometry (GC/MS). Analyses found several volatile compounds common to SIM and SD cards, as well as USB drives, including 2-propenenitrile, styrene, isophorone, hydroxycyclohexyl phenyl ketone, and 2-furanmethanol, tetrahydro. Results indicated that mass storage devices do have a characteristic odor profile making detection with minimal false alerts feasible for trained canines.