Forensic drug intelligence: an important tool in law enforcement

Organised criminality is a great concern for national/international security. The demonstration of complex crimes is increasingly dependant on knowledge distributed within law-enforcement agencies and scientific disciplines. This separation of knowledge creates difficulties in reconstructing and prosecuting such crimes. Basic interdisciplinary research in drug intelligence combined with crime analysis, forensic intelligence, and traditional law enforcement investigation is leading to important advances in crime investigation support. Laboratory results constitute one highly dependable source of information that is both reliable and testable. Their operational use can support investigation and even provide undetected connections or organisation of structure. The foremost difficulties encountered by drug analysts are not principally of a chemical or analytical nature, but methodologies to extract parameters or features that are deemed to be crucial for handling and contextualising drug profiling data. An organised memory has been developed in order to provide accurate, timely, useful and meaningful information for linking spatially and temporally distinct events on a national and international level (including cross-border phenomena). Literature has already pointed out that forensic case data are amenable for use in an intelligence perspective if data and knowledge of specialised actors are appropriately organised, shared and processed. As a particular form of forensic case data, the authors' research focuses on parameters obtained through the systematic physical and chemical profiling of samples of illicit drugs. The procedure is used to infer and characterise links between samples that originate from the same and different seizures. The discussion will not, however, focus on how samples are actually analysed and compared as substantial literature on this topic already exists. Rather, attention is primarily drawn to an active and close collaboration between magistrates, forensic scientists, law enforcement investigators and crime analysts from different institutions with the aim of generating, using and validating relevant profiling case data as integral part of investigative and crime analysis processes. Original advances are highlighted through experiences from criminal investigations of offences related to the unlawful importation, exportation, supply and possession of illicit drugs.     

Shoe print examinations: effects of expectation, complexity and experience

Even though trace evidence is becoming more and more important in legal cases, only little is known about the influence of task and context factors on comparative judgments. In the present study we investigated how expectations and complexity affect shoe print examinations and to what extent differences exist between beginners and experienced examiners. Twelve examiners assessed similarity between a shoe print and a shoe for eight different cases. For half the cases expectation was induced by providing additional incriminating evidence. A complex case meant that the print was relatively noisy, for example because the perpetrator rotated his foot. A simple case meant that the print was clear. The results showed that there was no effect of expectation and no effect of experience. Only complexity affected the examiners' assessments: when the background was noisy, the acquired features received a lower evidential value than when the background was clear. Apparently, examiners compensated for the quality of the print and were more cautious in drawing conclusions when prints were less clear. Even though the results allow for some optimism with regard to the influence of expectations on shoe print examinations, it has to be taken into account that the Dutch procedure is supported by a formal guideline, which may (partly) explain the present findings.     

Y-STRs in forensic medicine: DNA analysis in semen samples of azoospermic individuals

ABSTRACT: The incidence of rape has increased, especially in metropolitan areas, such as the city of São Paulo. In Brazil, studies about it have shown that the majority of this type of crime is committed by the relatives and persons close to the victim. This has made the crime more difficult to be denounced, as only 10% of the cases are reported to competent police authorities. Usually, cytological exams are carried out in sex crime investigations. The difficulty in showing the presence of spermatozoa is frequent, but it does not exclude the presence of male DNA. The absence of spermatozoa in material collected from rape victims can be due to several factors, including the fact that the agressor suffers from azoospermia. This condition can be the result of a successful vasectomy. As the majority of DNA in the ejaculation sample is from spermatozoa, there is much less DNA to be analyzed. This study presents the application of Y‐STRs (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) in DNA analysis of sperm samples from 105 vasectomized men. The study demonstrated a great variation in DNA concentration. DNA extraction and amplification was possible in all sperm samples even in the absence of spermatozoa. The same profile was observed, for each individual, from DNA extracted from blood, pre‐ and postvasectomy semen samples. The use of markers specific for Y chromosome in sex crime cases, especially in the absence of spermatozoa, is very important, mainly because in most situations there is a small quantity of the agressor's DNA in the medium and a large quantity of the victim's DNA.     

Virtual autopsy and forensic identification-practical application: a report of one case

The body of an unidentified elderly woman was found trapped in a floodgate. Prior to autopsy, full-body multislice computed tomography (MSCT) was performed for study of bone lesions and cause of death. Age was estimated by analysis of the sternal end of the fourth rib and of the pubic symphyseal medial articular surfaces. The results were then compared with the autopsy findings. MSCT was superior to autopsy in diagnosis of traumatic bone lesions and also revealed dental anomalies and signs of drowning. Age estimation gave a similar result for both methods. This case report illustrates the potential value of MSCT for medico-legal investigations of death: diagnosis of injuries, possibility of determining the cause of death, and anthropological study in order to estimate age or to visualize features likely to enable identification of a corpse.     

Recovery of Environmental Human DNA by Insects*,†

Abstract: We tested the hypotheses that foraging insects can acquire human DNA from the environment and that insect‐delivered human DNA is of sufficient quantity and quality to permit standard forensic analyses. Houseflies, German cockroaches, and camel crickets were exposed to dusty surfaces and then assayed for human mitochondrial and nuclear loci by conventional and qPCR, and multiplex STR amplification. Over two experiments, 100% of insect groups and 94% of dust controls tested positive for human DNA. Of 177 individuals, 33–67% tested positive and 13 yielded quantifiable human DNA (mean = 0.022 ± 0.006 ng; mean dust control = 2.448 ± 0.960 ng); four had at least one positive allele call for one or more locus; eight others showed multiple peaks at some loci. Results imply that application to routine forensic casework is limited given current detection methodology yet demonstrate the potential use of insects as environmental samplers for human DNA.     

Evaluation of a Freezer Mill for Bone Pulverization prior to DNA Extraction: An Improved Workflow for STR Analysis

Traditional methods for bone pulverization typically generate heat, risking stability of DNA sample. SPEX? has developed cryogenic grinders which introduce liquid nitrogen to cool the sample and aid in the grinding process. In this study, the Freezer Mill 6970 EFM was used with two DNA extraction methods and routine downstream STR analysis procedures. DNA from as little as 0.1 g of bone powder was used to develop full STR profiles after freezer mill pulverization, and the method was reproducible. Further, no contamination was detected upon cleaning/reuse of the sample vials. There were no significant differences in DNA yield, STR alleles detected, or peak heights using the freezer mill as compared to traditional grinding, and successful DNA profiles were achieved from as low as 0.1 g of bone powder with this method. Overall, this work indicates that this cryogenic mill method may be used as a viable alternative to traditional tissue grinders.     

Violence,Guns, and Suicide in New Orleans: Results from a Qualitative Study of Recent Suicide Decedents

Many Americans own guns to protect themselves against other people, but there is evidence that both victimization and gun access increase suicide risk. We conducted qualitative interviews with informants of 17 suicide cases in New Orleans of the 60 who died between January 2015 and April 2016 to understand the relationship between past trauma, gun access and storage, and suicide. Nine cases had experienced a past trauma, including three who had recently had a family member killed by homicide. Eight died via firearm; of those, seven owned the guns they used to take their lives and stored them locked (but loaded) at home or in their cars. Preventing community violence and addressing its sequelae may be important for reducing suicides. A multi‐pronged strategy consisting of policies, education, and marketing will likely be needed to address the risk of suicide conferred by gun access.     

Parents’ Perspectives on Family‐centered Care in Juvenile Justice Institutions

Family‐centered care during adolescent detention aims to increase parental participation in an attempt to optimize treatment outcomes. However, little is known about parents’ needs in family‐centered care. To fill this gap, we interviewed 19 purposefully selected parents of detained adolescents using a semi‐structured topic list. Although needs differed between parents, they were generally interested in activities that included spending time with their child. It is important for parents to receive timely information about their child's condition and treatment, detention procedures, and activities in the facility. The outcomes demonstrated that parents expected a two‐way communication based on respect and reliability.     

X‐ray Diffraction and Rietveld Refinement in Deferrified Clays for Forensic Science

Soil vestiges might provide information about a crime scene. The Rietveld method with X‐ray diffraction data (RM‐XRD) is a nondestructive technique that makes it possible to characterize minerals present in the soils. Soil clays from the metropolitan region of Curitiba (Brazil) were submitted to DCB treatment and analyzed using XRD with CuK_α radiation in the step‐scan mode (0.02° 2θ/5 s). The GSAS+EXPGUI software was used for RM refinement. The RM‐XRD results, together with the principal component analysis (PCA) (52.6% total variance), showed the kaolinite predominance in most analyzed samples and the highest quartz contents in “site 1.” Higher anatase, and gibbsite and muscovite contents influenced discrimination, mainly in “site 3” and “site 1,” respectively. These results were enough to discriminate clays of four sites and two horizons using a reduced amount of sample showing that the technique can be applied to the investigation into soil vestiges.