Forensic medicine experiences in cremation autopsy in Bonn

2016 coroner's crematorial inquests of the Bonn Institute of Legal Medicine over a 3 years' period were evaluated and the statements in the death certificates were compared to those ones of the Statistical Country Office of Northrhine-Westphalia. No significant differences were found with respect to age, gender and reason of death. However, the number of insufficiently classified deaths with respect to the reason of death were overrepresented especially in cases of older women, while the number of unnatural deaths was generally underrepresented. According to legal medical criteria 2 1/4 per cent of the deaths were falsely classified as natural. Only in 2 cases an autopsy was accomplished. Other author's statements on the validity of death certificates were confirmed.     

DNA contamination by examination instruments

Using DNA-analysis systems in forensic examination, conditions without any (iatrogenic) contamination are necessary for analysis of evidence. Failing these conditions a contamination is possible and interpretation of the results may be difficult. Our experiments demonstrated a relevant transfer of DNA-material if contaminated instruments were used.     

An unusual case of self-harm with petroleum distillate

After surgical treatment of an inguinal hernia, a 26-year-old male was discharged from hospital with a well healing surgical wound. Four weeks later he was admitted again with a major localized painful swelling of the soft tissues, whereas the clinical examination revealed no further local or systemic signs of inflammation. The immediate operation disclosed no abscess formation, but a large colliquation necrosis of the subcutaneous tissue with an outstanding petroleum-like odour. On toxicological examination of the necrotic tissue, a respective petroleum distillate was found. The patient was confronted with the suspicion of having injected the petroleum preparation himself to prolong the wound healing and finally admitted the self-mutilating behaviour. The pathophysiology, clinical history and morphological findings are discussed in comparison with case reports of chemically induced self-mutilation.     

Sex differences in proximal humeral outline shape: elliptical Fourier functions

A method is presented for the numerical analysis of sex differences in size and shape of the proximal humeral outlines using elliptical Fourier functions (EFFs). A skeletal sample consisting of right and left humeri pairs of 69 individuals, 36 males and 33 females, was used. The proximal superior view in the plane of the proximo-distal axis of each humerus was photographed and then 54 boundary points were located on the two-dimensional outline tracings. These points were digitized and used to compute EFFs with 27 harmonics. From the EFFs, a set of expected points on the proximal humeral outline was generated using the centroid as an origin. Superimposition of the male and female outlines on this centroid provided a detailed picture of the relative sex differences in size and shape with respect to that center. The bounded area of the proximal humeral outline showed statistically significant sex differences. Additionally, statistical results of the amplitudes derived from the "area-standardized" EFFs and visual assessments of the mean outline plots indicated significant sex differences in shape of the proximal humeral outlines. Focusing on localized regional differences, the greater tubercle was located more postero-medially and the lesser tubercle was located more anteriorly in the males compared to the females. Sex determinations from the proximal humeri were also examined with discriminant functions based on the amplitudes, which represent shape characteristics of the outline, and the hounded area. Using a cross-validation method, predictions of the percentages of cases correctly classified with the discriminant functions were ranged from 92.8% to 95.7% for the right and left humeral data. These results suggest that differences in size and shape of the proximal humeral outlines may be better predictors of sex when compared with conventional measurements of the humerus.     

Age estimation by occlusal tooth wear

The purpose of the present investigation was to test the accuracy of a new scoring system in recording tooth wear for age estimation. The material consisted of dental stone casts of 383 volunteers who had sound premolars and molars with normal occlusion. The degree of occlusal wear for all premolar and molar teeth was scored with the new system. The high intra- and inter-examiner concordances showed that the new score system was very reliable. The degree of tooth wear showed a significant positive correlation with age in each and every examined tooth of both males and females. Tooth wear scores of males were higher than those of females. Calculating tables for age estimation were designed and the accuracy of age estimation was obtained with the General Linear Models procedures. Our system could provide estimation of an individual's age within +/-3 years in 42.4% of males and 49.4% of females, within +/-5 years in 61.8% of males and 63.3% of females. When the subjects were divided into two age groups and data were re-treated, the accuracy of age estimation was increased. Collectively, it was shown that our new system for scoring tooth wear is a reliable and accurate method for age estimation.     

The FAA's postmortem forensic toxicology self-evaluated proficiency test program: the first seven years

Existing proficiency-testing (PT) programs do not address the complexity of postmortem forensic toxicology. These programs do not include decomposed samples and solid tissues. Therefore, the Federal Aviation Administration in July 1991 started such a needed PT program. This program is used to: (i) professionally develop and maintain technical currency on a voluntary, interlaboratory, and self-evaluation basis, and (ii) quantifiably assess methods in the absence and presence of interfering substances. There are currently about 30 laboratories in the program. Functioning under various governmental/non-governmental agencies and academic institutions, these laboratories represent a broad cross-section of the country. PT samples are distributed quarterly, and result summaries are sent to the participants, while maintaining their anonymity. Since the inception of the program, 28 PT samples encompassing whole blood, plasma, urine, kidney, or liver, with (or without) drugs, metabolites, and common chemicals (nicotine, caffeine, beta-phenylethylamine, etc.) have been analyzed by the participants. Analytical findings were generally consistent with the anticipated values, but they were dependent on the nature and conditions of the specimens and types of the added analytes. Some incidences of false positives of concern were noted, as well. This PT program is one of the few programs recommended by the American Board of Forensic Toxicology in which laboratories may participate for their accreditation by the Board. It is anticipated that this PT program will continue to play a critical part in supporting the quality assurance/quality control (QA/QC) component of forensic toxicology, thereby enhancing operational performance.