Carbon and Nitrogen Stable Isotope Analyses of Ephedra Plant and Ephedrine Samples and Their Application For Methamphetamine Profiling

In this study, stable isotope ratio analysis was used to track the precursor information of methamphetamine. The δ¹³C and δ¹⁵N values of 30 nature ephedra plants, 12 synthetic ephedrine/pseudoephedrine (ephedrine), 14 natural ephedrine, and 987 seized methamphetamine samples were measured and compared. Due to different weather and earth conditions, the δ¹³C and δ¹⁵N values of ephedra plants grown in the east and the west of Inner Mongolia showed great difference. The δ¹⁵N values of ephedra plants were consistent with related ephedrine extracted from them. Moreover, the criteria to infer the synthetic origin of ephedrine were set up after the analysis of natural and synthetic ephedrine samples. Finally, the precursor origins of 949 seized methamphetamine samples synthesized by Emde and Nagai method were tentatively inferred. Influenced by different preprecursors, the δ¹³C values of seized methamphetamine samples that synthesized from P2P also showed great difference, and this result is consistent with the reported data.     

Bioinformatics Approach to Assess the Biogeographical Patterns of Soil Communities: The Utility for Soil Provenance,

Soil DNA profiling has potential as a forensic tool to establish a link between soil collected at a crime scene and soil recovered from a suspect. However, a quantitative measure is needed to investigate the spatial/temporal variability across multiple scales prior to their application in forensic science. In this study, soil DNA profiles across Miami‐Dade, FL, were generated using length heterogeneity PCR to target four taxa. The objectives of this study were to (i) assess the biogeographical patterns of soils to determine whether soil biota is spatially correlated with geographic location and (ii) evaluate five machine learning algorithms for their predictive ability to recognize biotic patterns which could accurately classify soils at different spatial scales regardless of seasonal collection. Results demonstrate that soil communities have unique patterns and are spatially autocorrelated. Bioinformatic algorithms could accurately classify soils across all scales with Random Forest significantly outperforming all other algorithms regardless of spatial level.     

从心理迹证观点建构系统化现场勘察模式

本文从犯罪现场为基础,并以环境犯罪学观点,自国外实证研究结果就个人层级(理性选择理论)、社会互动层级(犯罪型态理论)、社会层级(日常活动理论)三种不同层次探讨性侵害加害者的决策模式(decision-making model)、犯罪空间型态(spatial patterns)、作案手法(modus operandi)与...     

Crime Mapping and the Training Needs of Law Enforcement

This paper explores some of the more recent developments within crime mapping and the broader application of geographical information technology within law enforcement. The information technology (IT) revolution and the reduction in computing costs since the 1980s has brought a range of analytical tools within the budgets of most police services, and one of the most significant changes has been in the way that spatial data are handled. Law enforcement has strong geographic currents at all levels of the organisation, and this paper examines three applications of geographical information systems (GIS) within policing: hotspot mapping; CompStat; and geographic profiling. The paper concludes by discussing the future training needs using a simple model of intelligence-led crime reduction. This model suggests that training for managers to enable a greater understanding of the analyses presented to them, and how to use mapping to further crime prevention and reduction, may be as important as increasing the technical ability of crime analysts. The challenge for the immediate future of crime reduction practice in law enforcement is less to worry about the training of analysts, and more to address the inability of law enforcement management to understand and act on the crime analysis they are given.     

Impurities,adulterants and cutting agents in cocaine as potential candidates for retrospective mining of GC-MS data

Cocaine is one of the most widely used illicit drugs worldwide. Cocaine powders seized by the Police may contain numerous other substances besides the drug itself. These can be impurities originating from the coca plant or the production process, or be purposely added to the drug formulation as adulterants and cutting agents. In forensic laboratories, identification of cocaine is routinely done through GC-MS analysis, but other components are often ignored even if the method allows for their detection. Yet, they can provide valuable insight into the history of a seizure and its potential connection to other samples. To explore this idea, an extensive review of common impurities and adulterants encountered in cocaine is presented. Based on their incidence, concentration in the end product and compatibility with GC-MS methods, their overall usefulness as candidates for the statistical investigation of existing forensic data is evaluated. The impurities cis- and trans-cinnamoylcocaine, tropacocaine, norcocaine and N-benzoylnormethylecgonine as well as the adulterants lidocaine, procaine, tetracaine, benzocaine, caffeine, acetylsalicylic acid, phenacetin, ibuprofen, levamisole, hydroxyzine and diltiazem are promising candidates to provide additional forensic intelligence. Future research on optimized routine GC-MS methods, signal reproducibility, comparison, statistics and databases is suggested to facilitate this concept. Ultimately, such an approach may significantly advance the amount of information that is extracted from routine casework data, elucidate developments in the cocaine markets in the past and facilitate Police work in the future. Preliminary assessment of existing data from the forensic laboratory of the Amsterdam Police has been included to show that the detection of the identified target impurities is feasible, and that small adjustments to the analysis method could significantly increase the detectability of these analytes in prospective drug screenings. Forensic intelligence based on retrospective data mining of cocaine containing casework samples may thus be realized with minimal additional laboratory efforts by using already available instrumentation, samples and data.     

Utility validation of extraction of genomic DNA from hard tissues, bone and nail, using PrepFiler™ Forensic DNA Extraction Kit

STR profiling using hard tissues obtained from a severely decomposed body is sometimes a laborious work. There is now on a market a new DNA extraction kit, PrepFiler™ Forensic DNA Extraction Kit (AppliedBiosystems), and we tested it for missing persons. Postmortem intervals ranged from weeks to several years. Fifteen bone fragments and eleven nails were used in this report. Genomic DNA was quantified by QuantiFiler^® DUO Quantification Kit (AppliedBiosystems), and STRs were analyzed using AmpFlSTR^® Identifiler^® PCR Amplification Kit (AppliedBiosystems). The profiling of 16 STR loci was successful in all nail samples. However, STR profiling was successful in only 6 of 15 bone materials. Nine cases failed to analyze STR polymorphisms using another DNA extraction kit, the QIAamp DNA Mini Kit (QIAGEN). For bone samples, it seems that STR profiling depends on the quality of samples.     

Chemical profiling of heroin recovered from the North Korean merchant vessel Pong Su

Heroin samples, seized from the North Korean merchant vessel Pong Su in Australian waters, were analyzed to determine geographic origin. Duplicate samples were analyzed by the National Measurement Institute's Australian Forensic Drug Laboratory and the United States Drug Enforcement Administration's Special Testing and Research Laboratory. Alkaloid ratios were determined by both liquid chromatography-diode array detection (LC-DAD) and capillary electrophoresis-diode array detection (CE-DAD) techniques. Acid/neutral manufacturing by-products were determined by solvent extraction followed by gas chromatography-mass spectrometry (GC-MS). Solvents, trapped in the heroin particles during manufacture, were detected by both static headspace GC-MS and purge and trap GC-MS. The alkaloid ratios obtained were consistent with heroin of a Southeast Asian (SEA) origin and principal component analysis of the alkaloid results demonstrated the presence of at least four subgroupings within the seizure. The solvent analysis detected diethyl ether and ethyl acetate, solvents typically seen in SEA heroin. However, the acid/neutral analysis revealed compounds not normally seen in heroin of a SEA origin. Furthermore, sterol-like molecules, always detected in the acid/neutral analysis of SEA heroin, were absent from the Pong Su samples. The Pong Su heroin, although similar to SEA heroin, has sufficient differences to classify it as having an unknown origin at the time of this writing.     

国外犯罪地理画像简介

犯罪地理画像是一种犯罪调查方法系统,它通过利用犯罪地和犯罪人基地之间的联系,以发现犯罪人最有可能的基地所在。国外犯罪地理画像的研究和应用已有较长时间,并有较大发展,其理论依据是环境犯罪学、坎特理论和犯罪的地理惯技。我国公安侦查工作可在应用范围、应用方法和步骤等方面借鉴国外的犯罪地理画像方式。     

DRIVING WHILE BLACK: BIAS PROCESSES AND RACIAL DISPARITY IN POLICE STOPS*

We estimate the degree of racial disparity in police vehicular stops separately for local and state police in North Carolina in the year 2000. We introduce four mechanisms that might produce racial disparities in police stops—racial profiling, race sensitive police deployment, cognitive bias and stereotyping, and prejudice. We then model the relative odds of police vehicle stops as a function of race, driving behavior, and other demographic statuses separately by police organization type, with controls for omitted variable bias at both the driver and spatial level. We find only weak evidence of racial disparity in stops by officers of the state highway patrol but stronger evidence in those made by local police officers.