Analytical methods used for the discrimination of substances suspected to be bar soap: a preliminary study

The submission to forensic laboratories of unknown specimens suspected of being biological or chemical warfare agents has increased tremendously with the threat of terrorism. Oftentimes, a threatening correspondence that contains hoax materials is intended to make the recipient(s) believe they have been exposed to a toxin. In some cases, the perpetrator can use standard household products, such as detergents and soaps. Once these materials are received, they become forensic evidence and may be analyzed for identification and/or comparison with known seized material from a suspect(s). Two separate studies were conducted using different analytical protocols for bar soaps. In the first set, the forensic laboratory at the United States Secret Service conducted tests on 68 bars of soap using solid-phase microextraction and gas chromatography coupled with mass spectrometry. The 68 different soaps displayed unique total ion chromatogram profiles. Energy-dispersive X-ray analysis in conjunction with scanning electron microscopy was also used to characterize 46 of the 68 soaps as a preliminary study. In a second set of studies, as part of a homicide investigation, the laboratory at the California Department of Justice, Riverside, conducted examinations on 13 bars of soap by utilizing Fourier transform-infrared spectroscopy. The case study demonstrated that it is possible to distinguish some bar soaps using infrared analysis. Furthermore, the bar soaps could be distinguished from typical laundry detergents using this technique.     

Violent media consumption and the recognition of dynamic facial expressions

This study assessed the speed of recognition of facial emotional expressions (happy and angry) as a function of violent media consumption. Color photos of calm facial expressions morphed to either an angry or a happy facial expression. Participants were asked to make a speeded identification of the emotion (happiness or anger) during the morph. Results indicated that, independent of trait aggressiveness, participants high in violent media consumption responded slower to depictions of happiness and faster to depictions of anger than participants low in violent media consumption. Implications of these findings are discussed with respect to current models of aggressive behavior.     

Suicide by drowning: a 20-year review

Drowning as a method of suicide is known to occur, but has primarily been described in environments with readily available access to water, such as coastal regions. In this study, we describe and analyze a series of suicidal drownings occurring in a noncoastal area of Texas. Between 1977 and 1996, 52 cases of suicidal drowning were investigated at the Southwestern Institute of Forensic Sciences in Dallas, Texas. Such deaths accounted for only 0.85% of all suicides and 4% of all drowning deaths. In contrast. suicidal drownings reportedly account for 2.8 to 8.9% of all suicides in regions with easy access to water. As with other studies of suicidal drowning, the victims are usually sober white males over the age of 40 years. Our results also confirm that certain individuals who commit suicide by drowning use weights to facilitate the process. A detailed analysis of the cases is provided. as is a synopsis of several questions that may aid in determining the manner of death in suicidal drowning cases.     

Sudden unexpected death resulting from hypothalamic sarcoidosis

The authors report a case of sudden death in a 23-year-old woman in whom autopsy by the medical examiner revealed hypothalamic sarcoidosis. The decedent had experienced 6 months of amenorrhea and a 50-pound weight gain. She sought medical attention when she experienced headache, and after imaging and laboratory studies, she was suspected of having neurosarcoidosis. She appeared to respond well to corticosteroid therapy. However, 6 weeks after the beginning of therapy, she was found dead on the floor of her residence. Autopsy showed extensive granulomatous inflammation of the hypothalamus and adjacent structures. Previously reported cases of hypothalamic sarcoidosis are reviewed. A hypothesis for the mechanism of sudden death is presented.     

Crime scene investigations using portable,non-destructive space exploration technology

The National Institute of Justice (NIJ) and the National Aeronautics and Space Administration's (NASAs) Goddard Space Flight Center (GSFC) have teamed up to explore the use of NASA developed technologies to help criminal justice agencies and professionals solve crimes. The objective of the program is to produce instruments and communication networks that have application within both NASA's space program and NIJ programs with state and local forensic laboratories. A working group of NASA scientists and law enforcement professionals has been established to develop and implement a feasibility demonstration program. Specifically, the group has focused its efforts on identifying gunpowder and primer residue, blood, and semen at crime scenes. Non-destructive elemental composition identification methods are carried out using portable X-ray fluorescence (XRF) systems. These systems are similar to those being developed for planetary exploration programs. A breadboard model of a portable XRF system has been constructed for these tests using room temperature silicon and cadmium-zinc telluride (CZT) detectors. Preliminary tests have been completed with gunshot residue (GSR), blood-spatter and semen samples. Many of the element composition lines have been identified. Studies to determine the minimum detectable limits needed for the analyses of GSR, blood and semen in the crime scene environment have been initiated and preliminary results obtained. Furthermore, a database made up of the inorganic composition of GSR is being developed. Using data obtained from the open literature of the elemental composition of barium (Ba) and antimony (Sb) in handswipes of GSR, we believe that there may be a unique GSR signature based on the Sb to Ba ratio.