Journal of Forensic Research

Human scent evidence has been used for centuries in various European countries and is now becoming more prevalent in the United States. Human scent evidence is collected either directly or indirectly and then used for scent discrimination with specially trained canines. The direct method allows the canine to smell an article of evidence, whereas the indirect method involves pre-scenting the canine with a sorbent material onto which traces of human scent have been previously collected. Even though there is no standardized collection material for human scent samples across various law enforcement agencies cotton based materials are commonly used. The purpose of this study was to investigate the ability of different types of sorbent materials, mainly cotton and cotton blend materials, to trap and release a combination of volatile organic compounds (VOCs) previously reported as human scent compounds. Volatile Organic Compounds in the headspace of the samples were extracted and identifi ed using solid-phase micro-extraction gas chromatography / mass spectrometry (SPME-GC/MS). The results showed that cotton blend materials released signifi cantly greater amounts of polar compounds when compared to the pure cotton materials. It appears that the chemical composition of the materials rather than the surface morphology plays the greater role in governing the trapping and releasing capabilities of the materials for human scent collection.

The blow fly larvae leave the food source after reaching maturity, and begin to disperse in order to fi nd suitable places for pupariation, a process commonly called postfeeding larval dispersal. Some important aspects of this process were studied by allowing the postfeeding larvae of Chrysomya megacephala (Fabricius) and Chrysomya rufi facies (Macquart) to disperse from the center of a circular arena. The arena was divided into 4 circles starting from the center in order to determine the location of each pupa. The relationship between distance from the center and the weight of each pupa was evaluated statistically. It was observed that the lighter larvae tend to move longer distances. The greatest concentration of pupae was found in distances lesser than 100 cm in both the species though it was more evident in case of C. rufi facies. The study of this dispersal process can be important while estimating the minimum postmortem
interval (PMI) of human cadavers during forensic investigations.

Mobile crime scene investigating team plays an important role to sorting numerous important and sensational crimes in Rajasthan (India). It is important that the crime scene investigator recognize that physical evidence recovered from these scenes may extend well beyond the conveyance itself. The nature of the crime may give the investigator an idea of the type of evidence present. In the present paper, a sensational case in the history of Rajasthan Forensic Science, in which four members of a family were found, died at their residence. Primarily, police was under dilemma that the family members were committed suicide or the incident was manipulated by the criminal i.e. they registered the case under 174 CrPC. During careful scientifi c observation of crime scene by the forensic team, it was advised to the Investigating Offi cer (I.O.) that it might possible homicidal rather than suicidal. On the direction of forensic scientist, the eldest son of family was arrested, which was also confi rmed by laboratory examination and in postmortem report.