The relationship between the detection of acquisitive crime by forensic science and drug-dependent offenders

Drug- and nondrug-related acquisitive crime offences such as burglary, theft, and motor vehicle theft, were compared to assess whether drug abusers were more likely to be apprehended via forensic science techniques. Data were all acquisitive offences committed over a 6-year period within a police force area in England. Drug-dependent offenders committed a wider range of offence types than nondependent offenders, and they were significantly more likely to be detected via their DNA or fingerprints (p < 0.01). A logistic regression (n > 14,000) revealed a number of predictors that influence the detection of the crime by forensic techniques. The results indicate that a number of these predictors are of statistical significance; the most significant of these being drug use by the offender with sex, ethnicity, and employment status also being relevant. Age of the offender and number of offences committed were found not to be significant. Of the four hypotheses considered to explain this, the most likely was thought to be the physical and mental impact of drug use on crime scene behavior. Consideration is given to the disciplines of forensic science and forensic psychology working closely together to distinguish factors that influence crime scene behavior.     

Percentage of body recovered and its effect on identification rates and cause and manner of death determination

Anthropologists frequently encounter cases in which only partial human remains are recovered. This study reports how the percentage of the body recovered affects identification (ID) rates and cause and manner of death determination. A total of 773 cases involving anthropology consults were drawn from the New Mexico medical examiner's office (1974-2006). Results indicate a significant correlation between body percent recovered and ID rates, which ranged from 89% for complete bodies to 56% when less than half the body was present. Similar patterns were evident in cause/manner determination, which were the highest (83% and 79%, respectively) in complete bodies but declined to 40% when less than half the body was found. The absence of a skull also negatively impacted ID and ruling rates. Findings are compared with general autopsy ID rates (94-96%) and cause/manner determination rates (96-99%) as well as prior published rates for individual casework and mass death events.     

A new method of reproduction of fingerprints from corpses in a bad state of preservation using latex

In view of the problems arising while fingerprinting corpses in a bad state of preservation, especially in case of mummification and carbonization, the authors propose an innovative technique which uses latex film. To better illustrate the potential of the method, two cases where the latex technique was applied successfully are reported: the first one is a mummified body discovered in a shack on the outskirts of Milan and the second one is the case of a burnt corpse found in a car boot. Such a technique is versatile, easy to apply, and allows the operator to work quickly on cadavers without amputating parts, except in rare cases (i.e., burnt bodies with muscle retraction). By the latex technique, a perfect and enduring negative copy of the fingerprint is obtained, ready to be inked and photographed. The numerous copies produced this way can be inked several times allowing for the repeatability of the procedure and this is crucial in cases of problematic legal identification of corpses. In both the cases illustrated, the fingerprints obtained by the latex technique were useful for identification. The quality was good enough for the automatic fingerprint identification system research system to be applied.     

Mitochondrial DNA identification of game and harvested freshwater fish species

The use of DNA in forensics has grown rapidly for human applications along with the concomitant development of bioinformatics and demographic databases to help fully realize the potential of this molecular information. Similar techniques are also used routinely in many wildlife cases, such as species identification in food products, poaching and the illegal trade of endangered species. The use of molecular techniques in forensic cases related to wildlife and the development of associated databases has, however, mainly focused on large mammals with the exception of a few high-profile species. There is a need to develop similar databases for aquatic species for fisheries enforcement, given the large number of exploited and endangered fish species, the intensity of exploitation, and challenges in identifying species and their derived products. We sequenced a 500bp fragment of the mitochondrial cytochrome b gene from representative individuals from 26 harvested fish taxa from Ontario, Canada, focusing on species that support major commercial and recreational fisheries. Ontario provides a unique model system for the development of a fish species database, as the province contains an evolutionarily diverse array of freshwater fish families representing more than one third of all freshwater fish in Canada. Inter- and intraspecific sequence comparisons using phylogenetic analysis and a BLAST search algorithm provided rigorous statistical metrics for species identification. This methodology and these data will aid in fisheries enforcement, providing a tool to easily and accurately identify fish species in enforcement investigations that would have otherwise been difficult or impossible to pursue.     

Identification of unknown bodies by using CT images of frontal sinus

The aim of the study was to define a simple system for the identification of unknown bodies by using CT images of frontal sinus and to discuss whether it was worth to add measurements to the system or not. The system was including simple features as F (presence or absence of frontal sinus), S (intersinus and intrasinus septum) and S (scalloping), and named as FSS system. Measurements selected for the study were width, height, anteroposterior length, total width of two sinuses, the distance between the highest points of the two sinuses and the distance of each sinus to its maximum lateral limit. The study was conducted retrospectively on the paranasal CT scans of 100 cases (38 male and 62 female) who had no apparent sinonasal pathology. All the features and measurements were coded according to the system defined by the authors for each case and coded formulas were compared. At least 93% of the formulas could be eliminated for a case by using FSS system. The rate of success was increased to 98% by adding measurements. Contrary to objective criteria of FSS system, measurements were prone to bias. Therefore, in practice success rate would be expected to be lower than calculated. In the study population, instead of making 100 measurements, eliminating the most of the cases with FSS system and later discriminating the rest by pattern matching was seen logical.     

Research note: evidence for moving to an 84-person photo lineup

The traditional six-to-ten person lineup is known to be extremely unreliable. Witnesses who choose someone when the suspect is innocent are too likely to choose that suspect. One solution is to enlarge the lineup in a manner that reduces mistaken identification far more than it lowers correct identification of the culprit. This experiment was built on past research, and it displayed to witnesses lineups consisting of sets of 12 photographs in an album, either two sets (24 photos) or seven sets (84 photos). No difference was found between witnesses for the 24-person lineup or the 84-person lineup in either their ability to identify the target whom they had seen previously, or in the number of mistaken choices of someone in lineups where the target was absent. Since the chance that the witness might mistakenly identify the suspect is far less in the 84-person lineup, lineups should consist of at least that number.

焦磷酸测序分析短片段牙釉质蛋白基因进行性别鉴定

目的采用焦磷酸测序技术分析短片段牙釉质蛋白基因进行性别鉴定并用于骨骼及腐败生物检材的检测。方法应用blast软件,确定牙釉质蛋白基因(Amel)上1段含有3个SNP位点及1个插入/缺失(indel)位点的序列作为待测靶序列,设计引物,扩增该段序列,应用焦磷酸测序技术分析扩增序列,进行性别鉴定。对方法进行准确性、灵敏度、种属特异性的测试,并用于对骨骼和高度降解DNA的检测。结果 PCR产物分别为44bp(Amel X)和45bp(Amel Y),女性测序结果为:G/G,T/T,…/…,C/C,男性测序结果为:G/T,T/A,…/C,C/A,分型图谱清晰。应用本文方法检测100份已知性别的DNA样本,结果均正确无误,方法最低DNA模板量为0.5ng,具有较好的人类种属特异性。用于高度降解DNA分析,较IdentifilerTM试剂盒具有更高的成功率且骨骼样本也得到清晰的分型结果。结论本文采用焦磷酸测序技术分析Amel的方法在法医学性别鉴定中有较好的应用价值。     

听辨在声纹鉴定中的作用

目的对言语特征进行研究,扩大声纹鉴定的应用范围。方法分析当前声纹鉴定的技术方法,汇总听辨结合的几种方法,找出听辨结合的关键点。结果对以往的鉴定经验和教训进行归纳总结,改进现有的鉴定模式和理念,使其贴近实战、贴近案件需求。     

Identification of synthetic cannabinoids in herbal incense blends in the United States

Abstract: Synthetic cannabinoid agonists are chemically diverse with multiple analogs gaining popularity as drugs of abuse. We report on the use of thin layer chromatography, gas chromatography mass spectrometry, high‐performance liquid chromatography, and liquid chromatography time of flight mass spectrometry for the identification and quantitation of these pharmacologically active chemicals in street drug dosage forms. Using these approaches, we have identified the synthetic cannabinoids JWH‐018, JWH‐019, JWH‐073, JWH‐081, JWH‐200, JWH‐210, JWH‐250, CP47,497 (C=8) (cannabicyclohexanol), RCS‐4, RCS‐8, AM‐2201, and AM‐694 in various commercially available products. Other noncannabinoid drugs including mitragynine have also been detected. Typical concentrations of drug in the materials are in the range 5–20 mg/g, or 0.5–2% by weight for each compound, although many products contained more than one drug.     

Species identification from dried snake venom

Illegal trade in snake parts has increased enormously. In spite of strict protection under wildlife act, a large number of snakes are being killed ruthlessly in India for venom and skin. Here, an interesting case involving confiscation of crystallized dried snake venom and subsequent DNA-based species identification is reported. The analysis using the universal primers for cytochrome b region of the mitochondrial DNA revealed that the venom was extracted from an Indian cobra (Naja naja). On the basis of this report, the forwarding authority booked a case in the court of law against the accused for illegal hunting of an endangered venomous snake and smuggling of snake venom. This approach thus has immense potential for rapid identification of snake species facing endangerment because of illegal trade. This is also the first report of DNA isolation from dried snake venom for species identification.