Analysis of 1989-1999 homicide crimes in the catchment area of the Bonn Institute of Forensic Medicine with reference to selected aspects

195 cases of homicide, grouped according to juridical assessment, were retrospectively analysed with regard to individual characteristics of perpetrators and victims, circumstances, and mode of commitment. The involvement of underage victims and perpetrators as well as differences between the urban and rural areas studied were taken into special consideration. To summarise, the majority of the offences studied was carried out by a male perpetrator with a mean age of 35 years driven by personal motives or greed in his immediate vicinity and affected family members or close acquaintances. The fatal injuries were mainly attributable to sharp or blunt force. With regard to killings of children, a higher prevalence of female victims and male assailants, emotional motives and an even higher importance of the social vicinity were found. Particularly in victims younger 12 years of age, manual modes of commitment without application of any tools were predominantly encountered. The comparison of urban and rural areas revealed a higher homicide rate in municipal areas especially of offences with a loose relationship between victims and assailants (greed, sexual assault). In contrast, rural areas exhibited higher rates of bodily harm with fatal consequences as well as offences by highly intoxicated assailants.     

Serum cannabinoid levels 24 to 48 hours after cannabis smoking

Low concentrations of THC and 11-hydroxy-THC in serum samples are often claimed not to result from recent cannabis use. Prediction of time of exposure is difficult, especially if distinctive features of drug use could not be observed. Therefore, the aim of the study was to investigate the presence of THC and 11-hydroxy-THC in serum samples as well as to obtain preliminary data on the analyte profile for a time window of 24-48 hours after discontinuation of cannabis smoking. Serum samples from heavy (n = 12, > 1 joint/day), moderate (n = 11, < or = 1 joint/day) and light (n = 6, < 1 joint/week) smokers of cannabis were analyzed for THC, 11-hydroxy-THC and free THC-COOH by GC/MS as well as for glucuronidated THC-COOH by LC/MS-MS. The blood samples were collected 24-48 hours after abstaining from cannabis use. Additionally, 8 specimens were obtained from persons after discontinuation of the drug for more than 48 hours. During collection of the blood samples, distinctive effects due to drug use could not be observed. For heavy users of cannabis, THC was detectable in 8 samples, and in 5 cases both biologically active compounds, THC and 11-hydroxy-THC, were present (1.3-6.4 ng THC/mL serum, 0.5-2.4 ng 11-hydroxy-THC/mL serum). Among moderate users, in 1 sample 1.8 ng THC/mL serum and 1.3 ng 11-hydroxy-THC/mL serum were determined, and another sample was tested positive with low concentrations close to the limit of detection. In serum samples of light users both analytes could not be detected, indicating that in those persons a positive finding of THC and 11-hydroxy-THC may rather result from recent consumption than from cannabis use 1 or 2 days prior to blood sampling. The concentrations of THC-COOH and its glucuronide covered a wide range in all groups of cannabis users. However, there was a trend to higher concentrations in heavy users compared to moderate users, and the mean concentration was smaller in light smokers than in moderate smokers. Overall, the findings indicated that data from pharmacokinetic studies should be supplemented by data obtained from "real-life" samples.     

Homicide attempt with a Japanese samurai sword

The use of Japanese swords for homicidal attempts is rare. A Japanese samurai sword is a sharp and cutting object. When faced with the use of this weapon, one must distinguish between stabs and incised wounds. Incised wounds can rarely lead to death, but because of the size of the weapon, stabs usually cause much more serious injuries. Stabs also imply a penetrating movement, whereas incised wounds can be the consequence of protective circular blows. Therefore, it is important to distinguish clinically between these two kinds of wounds. We report a case where the perpetrator argued he had given a circular blow, unfortunately hitting the victim. The pieces of evidence are discussed.     

Fatal diphenhydramine intoxication in infants

Diphenhydramine is an antihistamine available in numerous over-the-counter preparations. Often used for its sedative effects in adults, it can cause paradoxical central nervous system stimulation in children, with effects ranging from excitation to seizures and death. Reports of fatal intoxications in young children are rare. We present five cases of fatal intoxication in infants 6, 8, 9, 12, and 12 weeks old. Postmortem blood diphenhydramine levels in the cases were 1.6, 1.5, 1.6, 1.1 and 1.1 mg/L, respectively. Anatomic findings in each case were normal. In one case the child's father admitted giving the infant diphenhydramine in an attempt to induce the infant to sleep; in another case, a daycare provider admitted putting diphenhydramine in a baby bottle. Two cases remain unsolved; one case remains under investigation. The postmortem drug levels in these cases are lower than seen in adult fatalities. We review the literature on diphenhydramine toxicity, particularly as it pertains to small children, and discuss the rationale for treating these cases as fatal intoxications.     

STR DNA typing: increased sensitivity and efficient sample consumption using reduced PCR reaction volumes

Improvements in detection limits/sensitivity and lower sample consumption are potential benefits of reducing PCR reaction volumes used in forensic DNA typing of crime scene samples. This premise was studied first with experimental mixtures and a nine-loci megaplex, which demonstrated stochiometric amplification and accurate detection. Next, adjudicated casework samples were subjected to amplification under 15 different template DNA to PCR reaction volume ratios. Reduction of PCR reaction volume and DNA down to 10 microL and 0.500 ng, respectively, produced identical profiles with the same signal intensity and heterozygous allele peak height ratio (HR). Reduction to 5 microL and 0.063 ng yielded HR values that were slightly affected in one to three STR loci. PCR reaction volume reduction can enhance detection and sensitivity while reducing the consumption of irreplaceable crime scene samples.