Domestic accident or child abuse?

While playing, a 33/4-year-old girl was hiding in a tumble dryer, which had been running before and started the drying process with rotation of the drum again after the girl had climbed into the machine and shut the door. The child suffered multiple haematomas, especially on the back and the lower arms, as well as second-degree burns on body regions not covered by the clothing. The injury pattern was consistent with the properties of the appliance, and the initial suspicion that the child had been physically abused could not be maintained.     

Study of steroidogenesis in pupae of the forensically important blow fly Protophormia terraenovae (Robineau-Desvoidy) (Diptera: Calliphoridae)

Protophormia terraenovae is a forensically important fly whose development time is studied by forensic entomologists to establish the time elapsed since death (post-mortem interval, PMI). Quantity and nature of ecdysteroid hormones present in P. terraenovae pupae were analysed in order to determine if they could be correlated to the age of pupae found on corpses and thereby could give information on the PMI. Ecdysteroid levels were quantified during the pupal-adult development of synchronised animals using enzyme immunoassay (EIA), a sensitive method allowing acurate quantification in one pupa. Two types of pupae were compared: "fresh" pupae, kept frozen until analysis and "experimentally dried" pupae, which were left for several weeks at ambient temperature. A peak of ecdysteroids was detected between 36 and 96 h after pupariation in fresh animals. It was not observed in "experimentally dried" pupae. High-pressure liquid chromatography (HPLC) analyses combined with EIA showed that 20-hydroxyecdysone (20E) was the major free ecdysteroid at various pupal ages. Enzymatic hydrolysis experiments revealed the presence of apolar conjugates at all ages tested. However, neither qualitative nor quantitative difference was detected between early and late pupae. This study gives precise information on the nature and quantity of ecdysteroids in the course of pupal development of a calliphorid fly. The limits of using ecdysteroid measurement as a tool in forensic entomology are discussed.     

Results of the 2003-2004 GEP-ISFG collaborative study on mitochondrial DNA: focus on the mtDNA profile of a mixed semen-saliva stain

We report here a review of the seventh mitochondrial DNA (mtDNA) exercise undertaken by the Spanish and Portuguese working group (GEP) of the International Society for Forensic Genetics (ISFG) corresponding to the period 2003-2004. Five reference bloodstains from five donors (M1-M5), a mixed stain of saliva and semen (M6), and a hair sample (M7) were submitted to each participating laboratory for nuclear DNA (nDNA; autosomal STR and Y-STR) and mtDNA analysis. Laboratories were asked to investigate the contributors of samples M6 and M7 among the reference donors (M1-M5). A total of 34 laboratories reported total or partial mtDNA sequence data from both, the reference bloodstains (M1-M5) and the hair sample (M7) concluding a match between mtDNA profiles of M5 and M7. Autosomal STR and Y-STR profiling was the preferred strategy to investigate the contributors of the semen/saliva mixture (M6). Nuclear DNA profiles were consistent with a mixture of saliva from the donor (female) of M4 and semen from donor M5, being the semen (XY) profile the dominant component of the mixture. Strikingly, and in contradiction to the nuclear DNA analysis, mtDNA sequencing results yield a more simple result: only the saliva contribution (M4) was detected, either after preferential lysis or after complete DNA digestion. Some labs provided with several explanations for this finding and carried out additional experiments to explain this apparent contradictory result. The results pointed to the existence of different relative amounts of nuclear and mtDNAs in saliva and semen. We conclude that this circumstance could strongly influence the interpretation of the mtDNA evidence in unbalanced mixtures and in consequence lead to false exclusions. During the GEP-ISFG annual conference a validation study was planned to progress in the interpretation of mtDNA from different mixtures.     

Towards a "crime pollen calendar" - pollen analysis on corpses throughout one year

A palynological study was carried out on 28 corpses brought in one year (June 2003-May 2004) to the morgue of the Institute of Legal Medicine of Parma (Northern Italy). This preliminary research focuses on the date of death, which was known for all corpses examined. Pollen sampling and analyses were made with the first aim of comparing the pollen grains found on corpses with those diffused in the atmosphere in the region in the same season as the known date of death. Eyebrows, hair-line near the forehead, facial skin and nasal cavities were sampled. Most of the corpses had trapped pollen grains, with the exception of two December corpses. All pollen grains were found with cytoplasm and in a good state of preservation. In this way, a series of reference data was collected for the area where the deaths occurred, and we examined whether pollen grains on corpses could be an index of the season of death. To verify this hypothesis, the pollen analyses were compared with data reported in the airborne pollen calendars of Parma and the region around. Pollen calendars record pollen types and their concentrations in the air, month by month. The quantity of pollen recorded on corpses did not prove to be directly related to the quantity of pollen in the air. But qualitatively, many pollen types which are seasonal markers were found on corpses. Main corpse/air discrepancies were also observed due to the great influence that the local environmental conditions of the death scene have in determining the pollen trapped by a corpse. Qualitative plus quantitative pollen data from corpses appeared helpful in indicating the season of death. A preliminary sketch of a "crime pollen calendar" in a synthetic graphic form was made by grouping the corpse pollen records into three main seasons: A, winter/spring; B, spring/summer; C, summer/autumn. Trends match the general seasonal trend of pollen types in the air.     

STR data for nine Y-chromosomal loci in Guinea Equatorial (central Africa)

Allele and haplotype frequencies for nine Y-specific STR loci (DYS19, DYS389-I, DYS389-II, DYS390, DYS391, DYS393, DYS434, DYS437, and DYS439) were obtained from a sample of 57 males from Guinea Equatorial.     

Publications received

Publications Received

Publications received     

Duplications of the Y-chromosome specific loci P25 and 92R7 and forensic implications

In the present study, we demonstrate that two commonly used Y-chromosome single nucleotide polymorphisms (SNPs), P25 and 92R7, are paralogous sequence variants (PSVs) originating from segmental duplications and that at least one of the sequence variants in each group of loci is polymorphic. Several methodologies were used in order to detect the SNP alleles and the PSVs of the loci. All results obtained with the various typing techniques supported the conclusion. The allele distributions of the binary markers were analysed in more than 600 males with seven different haplogroups. For P25, the ancestral allele C was found in several samples from different haplogroups. The derived allele A was always present with an additional C variant. Haplogroup P was defined by the derived allele A at the 92R7 locus. However, the ancestral allele G was always associated with an A variant due to the duplication.