Changes in Attenuated Total Reflection Fourier Transform Infrared Spectra as Blood Dries Out

The time since deposition (TSD) of a bloodstain is a valuable piece of evidence for forensic scientists to determine the time at which a crime took place. The objective of this study was to determine whether attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy could be used to estimate the TSD of a bloodstain in a relatively early period (from 0 min to the time required for the bloodstain to dry out). For this purpose, we used ATR‐FTIR to study the variation in absorbance at certain wavelengths as rat and human blood sample dried out. The absorbance at 3308/cm (A3308) was found to have a close correlation with the TSD during this time period, and the changes in A3308 during the drying of rat and human blood drops under the same controlled conditions showed similar results. The current study indicates that ATR‐FTIR spectroscopy has potential as a tool for estimating TSD at early time periods of blood deposition.     

Only a Matter of Time? The Role of Criminal Competence in Avoiding Arrest

While prior research has shown that the probability of detection plays a role in the decision-making of many offenders, much less is known on offenders’ relative success in avoiding arrest. In this study, we draw from detailed criminal career data on 172 offenders involved in lucrative criminal activities to examine the role of criminal competence in the probability of being arrested in a given month. We examine a particular aspect of competence, criminal efficiency, which is defined as the ability to earn a relatively large amount of money for each crime committed. Our research design allows us to disentangle the effect of criminal efficiency as a static trait of offenders from the dynamic variations in efficiency that offenders experience over time. Results show that efficiency is a strong, negative predictor of arrest, both at the static and dynamic levels.     

Examining the Impact of Early Childhood School Investments on Neighborhood Crime

This study tested the hypothesis that investments in early childhood schools have short-term crime reducing effects in neighborhoods. Time series data from the city of Tulsa, Oklahoma, were analyzed to evaluate the effects of an early childhood school built in the neighborhood of Kendall-Whittier as part of a larger neighborhood revitalization plan, on violent and property crime. Results revealed that after controlling for city-wide crime trends and monthly fluctuations, violent crime declined significantly in Kendall-Whittier. Further analysis indicated that the possible crime-reducing effects of school investments on violent crime spread beyond Kendall-Whittier, and no displacement was found. The results for property crime were mixed. The study demonstrates the use of clustering analysis, a useful tool in neighborhood-level research to identify comparison neighborhoods. The findings shed light on the possibility that investments in early childhood schools can yield results in a shorter term than anticipated, making them a desirable component of urban revitalization.     

阿维菌素在急性中毒死家兔体内的再分布研究

目的考察阿维菌素在急性中毒死家兔体内的再分布。方法按最小致死量一次性灌胃250mg/kg阿维菌素,HPLC法检测家兔死后0h、24h、48h和72h中阿维菌素的含量。结果给家兔一次性灌胃250mg/kg阿维菌素的临床死亡时间为120.6±9.2min(±s,n=10);测定了阿维菌素的致死血浓度和致死组织浓度;家兔死后0h~72h心血和各主要脏器组织中阿维菌素含量存在体内再分布现象;确定肝、肾、肺为最佳组织检材。结论阿维菌素在急性中毒死家兔体内的再分布数据,对法医办理此类案件具有重要参考价值。     

狭义刑法解释若干问题探析

刑法解释只能在确切的刑法含义范围内进行解释 ,而不能超出刑法含义容量的最大界限。刑法解释应该以“自解释确定之日起施行”更加合适。刑法解释的效力及于刑法的施行期间 ,对于该解释实施前已生效的处理结果 ,应当从有利于被告人的原则来决定是否改判。     

日本近代刑法变革简述

刑法是国家之中的重要法律部门。日本自明治维新以来发生了深刻的变化,日本的刑法为了适应社会的发展而不断发生变化。到二次世界大战结束之前,发生了数次变革,这种变化发生的历程深刻体现着日本社会发展和法制发展进程中的被动性,而这种被动性中又有着很强的独立性。     

Validation of thin layer chromatography with AccuTOF-DART™ detection for forensic drug analysis

Abstract: Thin layer chromatography (TLC) is a technique that is commonly employed in the forensic drug analysis of pharmaceutical preparations. Detection is typically accomplished using various visualization spray reagents. Conventional gas chromatography–mass spectrometry (GC‐MS) analysis is typically performed to confirm the TLC results. Depending on the drugs tested and the instrument conditions required, this confirmation can take up to an hour to complete. Direct analysis in real time (DART?) is an ionization source, coupled to an accurate‐mass time‐of‐flight mass spectrometer that has the capability to ionize materials under ambient conditions. To streamline analysis, the combination of TLC with DART? detection is proposed to screen and subsequently identify drug compounds, all from the same TLC plate. DART? confirmations of TLC analyses take <10 min to complete and compare favorably to GC‐MS in sensitivity and selectivity. This study validates the use of TLC‐DART in the forensic identification of the components of several pharmaceutical preparations.     

Algor mortis: an erroneous measurement following postmortem refrigeration

Determination of the time of death is one goal of medicolegal death investigations. Algor mortis has been used as a measure of the postmortem interval (PMI). We prospectively recorded the core temperatures of 19 adult bodies entering our morgue cooler and at 3, 6, and 9 h of refrigeration. We then compared the cooling rate with the calculated body mass index (BMI). For each individual body, the rate of cooling was fairly linear with no evidence of a plateau. There was fair to moderate correlation between the BMI and the cooling rate: cooling rate = -0.052 (BMI) + 3.52. The probability of linearity in any given case was 36%. Variables affecting this correlation included the presence and the layers of clothing and if the clothing was wet. Our data confirm that algor mortis is of very limited utility in determining the PMI in bodies that have been refrigerated.     

Developmental validation of feline, bovine, equine, and cervid quantitative PCR assays

Accurate DNA quantification is essential for optimizing DNA testing and minimizing sample consumption. Real-time quantitative polymerase chain reaction (qPCR) assays have been published for human and canine nuclear DNA, and the need for quantifying other forensically important species was evident. Following the strategy employed for the canine qPCR assay, we developed individual assays to accurately quantify feline, bovine, equine, and cervid nuclear DNA. Each TaqMan-based assay incorporates a genus-specific probe targeting the Melanocortin-1 Receptor gene and includes a piece of synthetic DNA that acts as an internal PCR control for detecting inhibition. Developmental validations were carried out following the revised guidelines of the Scientific Working Group on DNA Analysis Methods with modifications necessary for validation of nonhuman qPCR assays. All assays demonstrated the specificity, sensitivity, stability, reproducibility, accuracy, and precision required for forensic casework. The application of these assays to animal forensic DNA analysis has both conserved laboratory resources and improved genotyping results.     

Laser desorption/ionization time-of-flight mass spectrometry of triacylglycerols and other components in fingermark samples

The chemical composition of fingermarks could potentially be important for determining investigative leads, placing individuals at the time of a crime, and has applications as biomarkers of disease. Fingermark samples containing triacylglycerols (TAGs) and other components were analyzed using laser desorption/ionization (LDI) time-of-flight mass spectrometry (TOF MS). Only LDI appeared to be useful for this application while conventional matrix-assisted LDI-TOF MS was not. Tandem MS was used to identify/confirm selected TAGs. A limited gender comparison, based on a simple t-distribution and peaks intensities, indicated that two TAGs showed gender specificity at the 95% confidence level and two others at 97.5% confidence. Because gender-related TAGs differences were most often close to the standard deviation of the measurements, the majority of the TAGs showed no gender specificity. Thus, LDI-TOF MS is not a reliable indicator of gender based on fingermark analysis. Cosmetic ingredients present in some samples were identified.