Collection and interpretation of “touch DNA” from crime scenes represent crucial steps during criminal investigations, with clear consequences in courtrooms. Although the main aspects of this type of evidence have been extensively studied, some controversial issues remain. For instance, there is no conclusive evidence indicating which sampling method results in the highest rate of biological material recovery. Thus, this study aimed to describe the actual considerations on touch DNA and to compare three different sampling procedures, which were “single-swab”, “double-swab”, and “other methods” (i.e., cutting out, adhesive tape, FTA^® paper scraping), based on the experimental results published in the recent literature. The data analysis performed shows the higher efficiency of the single-swab method in DNA recovery in a wide variety of experimental settings. On the contrary, the double-swab technique and other methods do not seem to improve recovery rates. Despite the apparent discrepancy with previous research, these results underline certain limitations inherent to the sampling procedures investigated. The application of this information to forensic investigations and laboratories could improve operative standard procedures and enhance this almost fundamental investigative tool’s probative value.

Fire deaths present several diagnostic challenges for the forensic examiner, the most significant of which is the identification of the cause of death and the evaluation of the morphological consequences of heat injuries in the ante-mortem and post-mortem periods. Here, we describe the case of two young lovers found dead inside a travelling carousel destroyed by a fire. Circumstantial evidence of disputes between families running the town fair raised the suspicion of intentional arson. Comparative analysis of crime scene investigation, radiological, autoptic, histological, and toxicological findings revealed signs of vitality (i.e., presence of soot deposits inside the respiratory and digestive tracts, heat damage to the respiratory mucosa) and identified fatal asphyxia from haemorrhagic pulmonary oedema as the cause of death. Since the experimental burning of plastic samples collected from a similar carousel demonstrated the significant production of phosgene, the death of the two lovers was attributed to the probable inhalation of this gas. The case presented here underlines the importance of a multidisciplinary approach of any fire-related death, providing an insight into circumstantial and forensic (autopsy, toxicological, and immunohistopathological) elements useful in raising suspicion of possible toxic gas inhalation. In the presence of high levels of PVC materials at the fire scene and pulmonary oedema at the autopsy, with no alternative causes of death, the forensic pathologist must suspect a fatal exposure to phosgene.