Suspicious circumstances on discovery of the cadaver

The authors report on three autopsy cases in which the findings at the death scene gave rise to the suspect of non-natural, in two cases even violent causes of death. The medico-legal and criminalistic investigations led to surprising results: Death was due to acute intoxication with narcotics, supposed delirium tremens and a suicide attempt in the presence of bronchopneumonia. External force was ruled out in all three fatalities by cooperative work of police investigators and forensic medicine.     

Fatal outcome of poisoning with the benzodiazepines flunitrazepam and diazepam

On a wintry day a 29-year-old woman was found dead beside her car showing head injuries and signs of hypothermia. Several empty packets of sedative and hypnotic drugs were lying inside the car. Toxicological analysis revealed the presence of flunitrazepam (heart blood of the left and right chamber 0.033 mg/L each), norflunitrazepam (left heart blood 0.029 mg/L, right heart blood 0.027 mg/L), 7-amino-flunitrazepam (left heart blood 0.090 mg/L, right heart blood 0.104 mg/L), diazepam (left heart blood 0.395 mg/L, right heart blood 0.386 mg/L), nordazepam (left heart blood 0.112 mg/L, right heart blood 0.115 mg/L) and temazepam (left heart blood 0.034 mg/L, right heart blood 0.033 mg/L). Neither alcohol nor other drugs were found. It was concluded that benzodiazepine intake led to a disturbance of consciousness. Whether the woman died in this situation due to the icy temperature as a result of hypothermia or whether she died or would have died solely due to benzodiazepine overdosage could not be clarified.     

Injury pattern in fatal automobile accident passengers due to rear-end collisions

The article reports on the injury pattern seen in fatally wounded car passengers after rear-end collisions on motorways. The study material included 5 rear-end collisions, in which 9 car occupants (5 drivers and 4 front-seat passengers) were killed. The change in velocity (delta v) was above 60 km/h in all the reported cases. The injury pattern showed the following characteristics: extensive soft-tissue traumatization (subcutaneous haematomas, blood-filled pockets, "décollements") not discernible from outside on the back of the trunk, mostly in the lumbosacral region; dorsal serial rib fractures, often combined with fractures of the spine (including the sacrum and the coccyx) and/or the pelvis; ruptures of the aorta at the typical sites of predisposition; ruptures of the liver and spleen (particularly at the visceral surfaces).     

Validation of a 16-locus fluorescent multiplex system

STR multiplexes have been indispensable for the efficient genotyping of forensic samples. The PowerPlex 16 System contains the coreCODIS loci, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, CSF1PO, FGA, THOI, TPOX, vWA, the sex determinant locus, amelogenin, and two pentanucleotide STR loci, Penta D and Penta E. This multiplex satisfies the locus requirements for most national databases and is the most efficient currently available system due to its single PCR amplification. To provide the groundwork for judicial acceptance, including the publication of primer sequences, and to evaluate laboratory-to-laboratory variation, a developmental validation for casework on this commercially available system was performed in 24 laboratories and produced the following conclusions. Amplification was reliable on a variety of thermal cyclers and product could be analyzed on either an ABI PRISM 310 Genetic Analyzer or an ABI PRISM 377 DNA Sequencer. Genotyping using single source samples was consistent between 0.25 and 2 ng of input DNA template with a few laboratories obtaining complete genotypes at 0.0625 ng. However, heterozygote allele imbalance (<60% peak height balance) caused by stochastic effects was observed at a rate of 13% with 0.125 ng DNA and 22% at 0.0625 ng DNA. Mixture analyses were done using a total of 1 ng of DNA template. Most alleles were detected in mixtures of 4 to 1 and some minor alleles were detected in mixtures of 19 to 1. Optimum amplification cycle number was dependent on the sensitivity of the detection instrument used and could also be adjusted to accommodate larger amounts of DNA on solid supports such as FTA paper. Reaction conditions including volume, annealing temperature, and concentrations of primer, AmpliTaq Gold, and magnesium were shown to be optimal yet robust enough to withstand moderate variations without affecting genotype analysis. Environmental, matrix and standard source analyses revealed an ability to obtain complete genotypes in all sample types except those exposed to 80 degrees C for 12-48 days. Finally, comparison of genotype results from the PowerPlex 16 System with other commercially available systems on non-probative reference and forensic samples showed consistent results.