Systematic differences in electropherogram peak heights reported by different versions of the GeneScan software

DNA profiling using STRs on the 310 and 3100 Genetic Analyzers routinely generates electropherograms that are analyzed with the GeneScan software available from the instrument's manufacturer, Applied Biosystems. Users have been able to choose from three different smoothing options that have been known to result in significant differences in the peak heights that are reported. Improvements in the underlying algorithm of the most recent version of the software also result in significant and somewhat predictable differences in peak height values. Laboratories that have performed validation studies using older versions of GeneScan should either reanalyze the data generated in those validation studies with the newest version of the software or otherwise take into consideration the systematically higher peak height values obtained as they begin following the recommendation of the manufacturer and use the new algorithm.     

Homicide with postmortem opening of the thoracic and abdominal cavity--morphological, criminological and forensic-psychiatric aspects

During a walk a man found the partially unclothed body of a 16-year-old girl in a field near a village in South Baden. The body showed numerous injuries caused by sharp force. Several stab wounds were discernible on the neck, the chest, the genital region, the back and the right thigh. Postmortem, the anterior wall of the trunk had been severed with one long cut reaching from the mons pubis to the jugular fossa. The injuries and the scene suggested homicide with a sexual motive. Already on the next day a male suspect was ascertained. Blood traces of the victim could be demonstrated on his car. The man confessed the homicide, but did not describe the course of events in detail. He denied a sexual motive for the homicide. The psychiatric examination did not furnish any clues to internal, neurological or psychiatric disorders. The perpetrator did not claim intoxication for the time of the offence, which might have been relevant for the question of criminal responsibility. Psychodiagnostically, it was found that he had a narcissistic personality structure with a pronounced lack of self-esteem, deficits in affect processing and control as well as anxiety and aggression problems. The man was sentenced to life imprisonment for murder.     

Forensic identification of dyes extracted from textile fibers by liquid chromatography mass spectrometry (LC-MS)

LC-MS is used for the identification of dyes extracted from textile fibers and the utility of the method for forensic trace analysis is demonstrated. The technique is shown to provide a high degree of chemical structural information, making dye identification highly specific in comparison to optical and/or chromatographic methods of dye analysis. A UV-visible absorbance detector, placed in series before the MS detector, facilitates monitoring the elution of dyes in the presence of other non-dye components extracted from colored textile fibers. In this way, dye identification becomes practical, even when a dye standard is not available for comparison. A set of 22 reference dyestuffs and 10 dyes extracted from textile fibers were analyzed to demonstrate the utility of the method. Six of the extracted dyes corresponded to dyes also contained in the set of 22 reference dyestuffs. Reference dyestuffs were not available for four of the extracted dyes. Triethylamine (TEA) was shown to increase the electrospray ionization-mass spectrometry (ESI-MS) response of dyes containing multiple sulfonated groups.