Y-chromosome STR system, Y-PLEX 12, for forensic casework: development and validation

The Y-PLEX 12 system, developed for use in human identification, enables simultaneous amplification of eleven polymorphic short tandem repeat (STR) loci, namely DYS392, DYS390, DYS385 a/b, DYS393, DYS389I, DYS391, DYS389II, DYS 19, DYS439 and DYS438, residing on the Y chromosome and Amelogenin. Amelogenin provides results for gender identification and serves as internal control for PCR. The validation studies were performed according to the DNA Advisory Board's (DAB) Quality Assurance Standards. The minimal sensitivity of the Y-PLEX 12 system was 0.1 ng of male DNA. The mean stutter values ranged between 3.76-15.72%. A full male profile was observed in mixture samples containing 0.5 ng of male DNA and up to 400 ng of female DNA. Amelogenin did not adversely affect the amplification of Y-STRs in mixture samples containing male and female DNA. The primers for the Y-STR loci present in Y-PLEX 12 are specific for human DNA and some higher primates. None of the primate samples tested provided a complete profile at all 11 Y-STR loci amplified with the Y-PLEX 12 system. Y-PLEX 12 is a sensitive, valid, reliable, and robust multiplex system for forensic analysis, and it can be used in human forensic and male lineage identification cases.     

Eyewitness Testimony in Occupational Accident Investigations: Towards a Research Agenda

Accident investigation is frequently cited as the cornerstone of an effective occupational health and safety program. We suggest that the literature on accident investigation is based on a model of witnesses as neutral and accurate recording devices. The literature on eyewitness testimony and criminal investigation offers strikingly different conclusions. We review these findings and point to their implication for research on accident investigation in occupational health and safety contexts.     

Demonstration of a gastric bioptic specimen mix-up by laser capture microdissection (LCM) and DNA fingerprinting

We demonstrate here the successful use of laser capture microdissection (LCM) and DNA fingerprinting in the identification of a case of gastric bioptic specimen mix-up. A 70-year-old man, suffering from chronic atrophic gastritis, underwent to a gastric biopsy and received a diagnosis of gastric cancer. In the absence of any clinical evidence of gastric cancer, a specimen mix-up was suspected. LCM was used to retrieve gastric cells from the histologic slide, classified as gastric carcinoma, and suspected to be mislabelled. DNA was extracted from microdissected cells, and a total of 16 different genetic loci were analyzed, using an identity test. Comparison of the results with those obtained using DNA extracted from a control slide, and from patient's saliva, demonstrated a distinct DNA fingerprint pattern in all genetic markers examined, clearly indicating the occurrence of a specimen mix-up. The combined use of LCM and DNA fingerprinting represents the most accurate and sophisticated method available for the identification of specimen mix-up, especially when only the tissue on the suspected slide is available.     

Allele frequencies data and statistic parameters for 16 STR loci-D19S433, D2S1338, CSF1PO, D16S539, D7S820, D21S11, D18S51, D13S317, D5S818, FGA, Penta E, TH01, vWA, D8S1179, TPOX, D3S1358-in the Rio de Janeiro population, Brazil

Allele frequencies for 16 short tandem repeats (STR) loci were determined with a sample of 230-300 unrelated individuals from the population of Rio de Janeiro, Brazil. The loci are the most commonly used in forensic and paternity testing, being analysed by the Identifiler (Applied Biosystems) and PowerPlex 2.1 (Promega) commercial kits. It was proved that Penta E and D18S51 are the most polymorphic loci.     

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.     

Detecting Deception in Children's Testimony: Factfinders' Abilities to Reach the Truth in Open Court and Closed-Circuit Trials

This study examined the influence of closed-circuit television (CCTV) on jurors' abilities to detect deception in children's testimony. Children ages 7–9 individually played games and made a video movie with a male confederate. In the guilty condition, stickers were placed on exposed body parts (i.e., the child's arm, toes, and bellybutton). In the not-guilty and deception conditions, stickers were placed on the child's clothing rather than on bare skin. Approximately 3 weeks later, mock jurors recruited from the community viewed child participants testify either in a traditional courtroom setting or via one-way CCTV. The mock jurors responded to questions about the child witness and the defendant as well as deliberated to reach a verdict. Children in the deception condition were asked to testify as if the stickers had been placed on exposed body parts rather than on their clothing. Predeliberation, jurors were less likely to convict when a child testified in the deception condition as opposed to the guilty condition. These differences disappeared following deliberation. There was no support for the notion that jurors reach the truth better when children testify in open court versus via CCTV. Implications for jurors' abilities to reach the truth are discussed.     

Use of the MMPI-2 and the Inwald personality inventory to identify the personality characteristics of dropouts from a state police academy

The MMPI-2 and the Inwald Personality Inventory were employed to investigate the personality characteristics of dropouts from a state police academy. A traditional model of training borrowed from military models was used at the academy rather than a police generated model. Sensitive and independent individuals, more compatible with modern community policing methods may have rejected police work as a result of the experience. 15 academy completers and 9 dropouts were used in the sample. Analyses of the scales of the MMPI-2 and the Inwald Personality Inventory identified variables upon which the two groups differed. The hypothesis that more sensitive, empathic and independent individuals were leaving the academy appeared to be supported.