Quantitative/Statistical Approach to Bullet-to-Firearm Identification with Consecutively Manufactured Barrels

Efforts to use objective image comparison and bullet scanning technologies to distinguish bullets from consecutively manufactured handgun barrels from two manufacturers gave mixed results. The ability of a technology to reliably distinguish between matching and non-matching bullets, where the non-matching bullets were as close in pattern to the matching ones as is probably possible, would provide evidence that the distinctions could be made ''objectively'', and independently of human eyes. That evidence is identical or very close to what seems to be needed to satisfy Daubert standards. It is fair to say that the FTI IBIS image comparison technology correctly distinguished between all the Springfield barrel bullets, and between most but not all of the HiPoint barrel bullets. In the HiPoint cases that were not distinguished 100% of the time, they would he distinguished correctly at least 83% of the time. These results, although obviously limited to the materials used in the comparisons, provide strong evidence that barrel-to-bullet matching is objectively reliable. The results with SciClops were less compelling. The results do not mean that bullet-to-barrel matching is not objectively reliable--rather, they mean that this version of the particular technology could not quite distinguish between these extremely similar yet different bullets as well as the image comparison technology did. In a number of cases, the numerical results made the correct distinctions, although they were close to one another. It is hard to say from this data that this technology differs in its ability to make distinctions between the manufacturers, because the results are very similar with both. The human examiner results were as expected. We did not expect any misidentifications, and there were not any. It would have been preferable to have a higher return rate, and thus more comparisons in the overall sample. As noted, the ''consecutively manufactured barrel exercise'' has been done before, with the same outcome

Forensic application of a rapid one-step tetramethylbenzidine-based test for the presumptive trace detection of bloodstains at the crime scene and in the laboratory

Bloodstains are a widespread kind of biological evidence at the crime scene and one of the most used reagents for the presumptive identification of blood for forensic purposes is tetramethyl-benzidine. We have introduced and validated the tetramethylbenzidine-based Combur3 Test® E (Roche Diagnostics Corporation, Basel, Switzerland), a colorimetric catalytic test based upon the detection of the peroxidase-like activity of the hemoglobin, due to its high sensitivity, easiness of use and capability to maintain the complete structural and morphological integrity of the bloodstain. Analytical performances related to a forensic use of the test and the suitable applicability to the presumptive detection of bloodstains when extremely diluted, aged, mixed with several substances and deposited over a plethora of substrates was reliably proved. In addition, possible positive interferences of the test chemicals on the subsequent Short Tandem Repeats (STRs) DNA typing analyses, especially in Low-Template DNA (LT DNA) conditions, was evaluated. While the Combur3 Test® E showed the same chemical interference drawbacks as other presumptive tests for blood as for the low specificity, we demonstrated that its format and our suggested protocol of use make it appropriate for the forensic presumptive detection of blood, better performing and much easier to use than other analogous presumptive tests and usually compatible with the following STRs DNA typing analyses

Haptoglobin Phenotype, Preeclampsia Risk and the Efficacy of Vitamin C and E Supplementation to Prevent Preeclampsia in a Racially Diverse Population

Haptoglobin's (Hp) antioxidant and pro-angiogenic properties differ between the 1-1, 2-1, and 2-2 phenotypes. Hp phenotype affects cardiovascular disease risk and treatment response to antioxidant vitamins in some non-pregnant populations. We previously demonstrated that preeclampsia risk was doubled in white Hp 2-1 women, compared to Hp 1-1 women. Our objectives were to determine whether we could reproduce this finding in a larger cohort, and to determine whether Hp phenotype influences lack of efficacy of antioxidant vitamins in preventing preeclampsia and serious complications of pregnancy-associated hypertension (PAH). This is a secondary analysis of a randomized controlled trial in which 10,154 low-risk women received daily vitamin C and E, or placebo, from 9-16 weeks gestation until delivery. Hp phenotype was determined in the study prediction cohort (n = 2,393) and a case-control cohort (703 cases, 1,406 controls). The primary outcome was severe PAH, or mild or severe PAH with elevated liver enzymes, elevated serum creatinine, thrombocytopenia, eclampsia, fetal growth restriction, medically indicated preterm birth or perinatal death. Preeclampsia was a secondary outcome. Odds ratios were estimated by logistic regression. Sampling weights were used to reduce bias from an overrepresentation of women with preeclampsia or the primary outcome. There was no relationship between Hp phenotype and the primary outcome or preeclampsia in Hispanic, white/other or black women. Vitamin supplementation did not reduce the risk of the primary outcome or preeclampsia in women of any phenotype. Supplementation increased preeclampsia risk (odds ratio 3.30; 95% confidence interval 1.61-6.82, p<0.01) in Hispanic Hp 2-2 women. Hp phenotype does not influence preeclampsia risk, or identify a subset of women who may benefit from vitamin C and E supplementation to prevent preeclampsia

Distributions of Genetic Markers in a Nebraska Population

Seven genetic marker systems were analyzed from liquid blood and dried bloodstain specimens submitted to the Nebraska State Patrol Crime Laboratory from various law enforcement agencies throughout Nebraska. The phenotypic and genotypic frequencies for the ABO, Lewis, esterase D (ESD), pbosphoglucomutase (PGM), adenylate kinase (AK), adenosine deaminase (ADA), and haptoglobin (HP) systems were calculated. The results indicate that the phenotypic frequencies are generally in agreement with frequencies reported in other populations in the United States