Enhancing the Visibility of Injuries with Narrow‐Banded Beams of Light within the Visible Light Spectrum

The use of narrow‐banded visible light sources in improving the visibility of injuries has been hardly investigated, and studies examining the extent of this improvement are lacking. In this study, narrow‐banded beams of light within the visible light spectrum were used to explore their ability in improving the visibility of external injuries. The beams of light were induced by four crime‐lites^® providing narrow‐banded beams of light between 400 and 550 nm. The visibility of the injuries was assessed through specific long‐pass filters supplied with the set of crime‐lites^®. Forty‐three percent of the examined injuries improved in visibility by using the narrow‐banded visible light. In addition, injuries were visualized that were not visible or just barely visible to the naked eye. The improvements in visibility were particularly marked with the use of crime‐lites^® “violet” and “blue” covering the spectrum between 400–430 and 430–470 nm. The simple noninvasive method showed a great potential contribution in injury examination.     

Study of the Behaviors of Gunshot Residues from Spent Cartridges by Headspace Solid‐Phase Microextraction–Gas Chromatographic Techniques

Gunshot residues, produced after shooting activity, have acquired their importance in analysis due to the notoriety of firearms‐related crimes. In this study, solid‐phase microextraction was performed to extract the headspace composition of spent cartridges using 85‐μm polyacrylate fiber at 66°C for 21 min. Organic compounds, that is, naphthalene, 2,6‐dinitrotoluene, 2,4‐dinitrotoluene, diphenylamine, and dibutyl phthalate were detected and analyzed by gas chromatography‐flame ionization detection technique. Evaluation of chromatograms for diphenylamine, dibutyl phthalate, and naphthalene indicates the period after a gunshot was discharged, whether it was 1 days, 2–4 days, <5 days, 10 days, 20 days, or more than 30 days ago. This study revealed the potential effects of environmental factors such as occasional wind blow and direct sunlight on the estimation of time after spent cartridges were discharged. In conclusion, we proposed reliable alternative in analyzing the headspace composition of spent cartridges in a simulated crime scene.     

Criminal Behavior in Opioid‐Dependent Patients Before and During Maintenance Therapy: 6‐year Follow‐Up of a Nationally Representative Cohort Sample

Lifetime prevalence of opioid dependence is about 0.4% in western countries. Opioid‐dependent patients have high morbidity and mortality and a high risk of criminal behavior. Few studies have addressed the long‐term impact of opioid maintenance therapy on convictions and criminal behavior. The PREMOS study is a prospective, longitudinal, naturalistic clinical study of a nationally representative sample of 2694 opioid‐dependent patients to investigate convictions and criminal behavior at baseline and after 6 years of maintenance treatment. At follow‐up, 2284 patients still were eligible (84.7%). A comprehensive assessment including a patient and doctor questionnaire, and the EuropASI was completed at baseline and follow‐up. Data on criminality at follow‐up had been received for 1147 (70.6%) patients. A large number (84.5%) of them had been charged or convicted at any time before baseline assessment, most frequently with drug‐related offenses (66.8%), acquisitive crime (49.1%), or acts of violence (22.0%). Reported charges and convictions had declined to 17.9% for the last 12 months before follow‐up, which was also reflected by a significant decrease in the EuropASI subscore “legal problems” from 1.52 at baseline to 0.98 after 6 years. These data indicate a significant and clinically relevant reduction in criminal behavior in opioid‐dependent patients in long‐term maintenance treatment. Maintenance therapy is effective in the reduction in both narcotics‐related and acquisition crime.     

DNA in the Criminal Justice System: The DNA Success Story in Perspective,

Current figures on the efficiency of DNA as an investigative tool in criminal investigations only tell part of the story. To get the DNA success story in the right perspective, we examined all forensic reports from serious (N = 116) and high‐volume crime cases (N = 2791) over the year 2011 from one police region in the Netherlands. These data show that 38% of analyzed serious crime traces (N = 384) and 17% of analyzed high‐volume crime traces (N = 386) did not result in a DNA profile. Turnaround times (from crime scene to DNA report) were 66 days for traces from serious crimes and 44 days for traces from high‐volume crimes. Suspects were truly identified through a match with the Offender DNA database of the Netherlands in 3% of the serious crime cases and in 1% of the high‐volume crime cases. These data are important for both the forensic laboratory and the professionals in the criminal justice system to further optimize forensic DNA testing as an investigative tool.     

Learning on the job: Studying expertise in residential burglars using virtual environments*

In this article, we describe a quasi‐experiment in which experienced incarcerated burglars (n = 56), other offenders (n = 50), and nonoffenders (n = 55) undertook a mock burglary within a virtual neighborhood. We draw from the cognitive psychology literature on expertise and apply it to offending behavior, demonstrating synergy with rational choice perspectives, yet extending them in several respects. Our principal goal was to carry out the first robust test of expertise in offenders by having these groups undertake a burglary in a fully fledged reenactment of a crime in a virtual environment. Our findings indicate that the virtual environment successfully reinstated the context of the crime showing clear differences in the decision making of burglars compared with other groups in ways commensurate with expertise in other behavioral domains. Specifically, burglars scoped the neighborhood more thoroughly, spent more time in the high‐value areas of the crime scene while traveling less distance there, and targeted different goods from the comparison groups. The level of detail in the data generated sheds new light on the cognitive processes and actions of burglars and how they “learn on the job.” Implications for criminal decision‐making perspectives and psychological theories of expertise are discussed.     

Evaluating the use of hypoxia sensitive markers for body fluid stain age prediction

To augment DNA profiling and body fluid identification techniques efforts are being made to increase the amount of information available from a crime scene stain, which includes efforts to identify externally visible characteristics through phenotypic analysis. A key question surrounding crime scene stains is the length of time between deposition of the stain and its subsequent recovery, in that is the stain recovered related to the incident in question or from a previously deposited stain number of weeks earlier? The inability to answer this fundamental question has a detrimental effect upon the successful completion of a criminal investigation. Once a body fluid leaves the body, the oxygen concentration in the environment changes; therefore, it may be that this change could cause a change in the expression of hypoxia-sensitive biomarkers. Here, a range of bloodstains, liquid saliva and liquid semen samples were collected at 0 days, 7 days, 14 days, 21 days and 28 days of degrading at room temperature (19–22 °C), before undergoing total RNA extraction and cDNA synthesis. Blood was recovered from filter paper with 3 mm², with saliva and semen being left in their tubes and swabbed at the appropriate times. All samples then underwent quantitative PCR targeting Vascular Endothelial Growth Factor A (VEGFA) and Hypoxia-Inducible Factor 1 Alpha (HIF1A), with B-Actin (ACTB) as a reference gene. A range of linear and quadratic correlation values was obtained from the qPCR data and used to develop a predictive model with a mean absolute deviation (MAD) of 4.2, 2.1, and 5 days for blood, saliva, and semen respectively. Blind testing indicated that a stain age prediction model based upon VEGFA with ACTB as a reference gene could be used on samples up to four weeks old with a margin of error ranging from 2 days through to 5 days. While a sizeable potential time frame exists using this model; this represents a significant step towards the target of having an accurate stain age prediction model.     

Identification of furosemide in hair in a post‐mortem case by UHPLC‐MS/MS with guidance on interpretation

Testing for drugs in hair raises several difficulties. Among them is the interpretation of the final concentration(s). In a post‐mortem case, analyses revealed the presence of furosemide (12 ng/mL) in femoral blood, although it was not part of the victim's treatment. The prosecutor requested our laboratory to undertake an additional analysis in hair to obtain information about the use of furosemide. A specific method was therefore developed and validated to identify and quantify furosemide in hair by UHPLC‐MS/MS. After decontamination of 30 mg of hair, incubation in acidic condition, extraction with ethyl acetate, the samples were analyzed by UHPLC‐MS/MS. Furosemide was found in the victim's hair at 225 pg/mg. However, it was not possible to interpret this concentration due to the absence of data in the literature. Therefore, the authors performed a controlled study in two parts. In order to establish the basis of interpretation, several volunteers were tested (four after a single 20 mg administration and twenty‐four under daily treatment). The first part indicated that a single dose is not detectable in hair using our method. The second part demonstrated concentrations ranging from 5 to 1110 pg/mg with no correlation between dosage and hair concentrations. The decedent's hair result was interpreted as repeated exposures. In the case of furosemide analysis, hair can provide information about its presence but cannot give information about dosage or frequency of use.     

The age estimation of blood stains up to 30 days old using visible wavelength hyperspectral image analysis and linear discriminant analysis

A novel application of visible wavelength hyperspectral image analysis has been applied to determine the age of blood stains up to 30 days old. Reflectance spectra from selected locations within the hyperspectral image, obtained from a portable instrument, were subjected to spectral pre-processing. This was followed by the application of a linear discriminant classification model, making estimations possible with an average error of ± 0.27 days for the first 7 days and an overall average error of ± 1.17 days up to 30 days. This is also the first reported study of the determination of the age of fresh blood stains (less than one day old) with an error of ± 0.09 h. The studies have been made under controlled conditions and represent, at this stage, proof of concept results but also are the most accurate age estimation results for measurements between 0 and 30 days reported to date. The results are consistent with well-established kinetic processes suggesting that the pre-processing stages described are revealing spectroscopic changes which are reliably following the time dependent oxidation of HbO₂. The potential for parameterisation of environmental factors to make the method generally applicable at crime scenes is discussed, along with the developments required to further improve classification and to make the instrument genuinely portable.     

Development of a Protein‐based Human Identification Capability from a Single Hair

Shed human hair (lacking root nuclear DNA) frequently contributes important information to forensic investigations involving human identification. Detection of genetic variation observed in amino acid sequences of hair proteins provides a new suite of identity markers that augment microscopic hair analysis and mitochondrial DNA sequencing. In this study, a new method that completely dissolves single hairs using a combination of heat, ultrasonication, and surfactants was developed. Dissolved proteins were digested and genetically variant peptide (GVP) profiles were obtained for single hairs (25 mm) via high‐resolution nanoflow liquid chromatography‐based mass spectrometry and a novel exome‐driven bioinformatic approach. Overall, 6519 unique peptides were identified and a total of 57 GVPs were confirmed. Random match probabilities ranged between 2.6 × 10^?2 and 6.0 × 10^?9. The new bioinformatic strategy and ability to analyze GVPs in forensically relevant samples sizes demonstrate applicability of this approach to distinguish individuals in forensic contexts.     

Evaluation of Postmortem Bacterial Migration Using Culturing and Real‐Time Quantitative PCR

Postmortem bacteriology can be a valuable tool for evaluating deaths due to bacterial infection or for researching the involvement of bacteria in various diseases. In this study, time‐dependent postmortem bacterial migration into liver, mesenteric lymph node, pericardial fluid, portal, and peripheral vein was analyzed in 33 autopsy cases by bacterial culturing and real‐time quantitative polymerase chain reaction (RT‐qPCR). None suffered or died from bacterial infection. According to culturing, pericardial fluid and liver were the most sterile samples up to 5 days postmortem. In these samples, multigrowth and staphylococci were not or rarely detected. RT‐qPCR was more sensitive and showed higher bacterial positivity in all samples. Relative amounts of intestinal bacterial DNA (bifidobacteria, bacteroides, enterobacter, clostridia) increased with time. Sterility of blood samples was low during the studied time periods (1–7 days). The best postmortem microbiological sampling sites were pericardial fluid and liver up to 5 days after death.     

When stereotypes backfire: Trying to suppress stereotypes produces false recollections of a crime

Purpose . This study examined whether participants' memories of a racially neutral crime story are influenced by stereotypes and the instruction to suppress stereotypes while reading the crime story. We expected that participants who saw a photograph of a foreign group (negative stereotype prime) and were given the instruction to suppress stereotypes before reading a crime story would make significantly more stereotype‐consistent errors on a recognition test than participants who received a neutral prime and a suppression instruction. Methods . Participants were 88 undergraduate students (59 women) who were randomly allocated to the cells of a 2 (negative stereotype versus neutral prime)×2 (thought suppression versus control) between‐subjects design. The dependent variables were recognition of accurate items, stereotype‐consistent items and confabulation items. Results . The critical stereotype × suppression interaction was statistically significant for false recognition of non‐presented stereotype‐consistent items. Simple effect analyses of the suppression condition showed that participants who were primed with a negative stereotype made more stereotype‐consistent recognition errors than those who had been exposed to a neutral prime. Conclusions . Stereotypes not only make cognitive processing easier, but might also contribute to recognition errors when people do what they often are told to do in the legal arena: suppress stereotypical thinking.     

Police Officers on Drug Corners in Philadelphia,Drug Crime,and Violent Crime: Intended,Diffusion, and Displacement Impacts

On May 1, 2002, the Philadelphia Police Department launched Operation Safe Streets, stationing officers at 214 of the highest drug activity locations in the city 24 hours a day, 7 days a week. Interrupted time series (AutoRegressive Integrated Moving Average) models on weekly data isolated citywide and local program impacts on all violent crimes, murder, and reported drug crimes. Results showed no significant impacts on citywide weekly counts for drug crimes, homicides, or all violent crimes. Geographically focused analyses showed significant localized intervention impacts for both violent and drug crimes. Analyses of high‐drug‐activity non‐intervention sites suggest: the program impacts seen were not an artifact of history or local history; significant spatial diffusion of preventive benefits for violent crime; and probably significant spatial displacement for drug crime. Stationary targeted drug‐enforcement interventions like Operation Safe Streets may differentially affect the locational selection processes behind violent crime versus drug crime.     

Simultaneous analysis of six amphetamines and analogues in hair, blood and urine by LC-ESI-MS/MS: Application to the determination of MDMA after low Ecstasy intake

A rapid and sensitive method using LC-MS/MS triple stage quadrupole for the determination of traces of amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA, “ecstasy”), 3,4-methylenedioxyethamphetamine (MDEA), and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB) in hair, blood and urine has been developed and validated. Chromatography was carried out on an Uptisphere ODB C₁₈ 5 μm, 2.1 mm × 150 mm column (Interchim, France) with a gradient of acetonitrile and formate 2 mM pH 3.0 buffer. Urine and blood were extracted with Toxitube A^® (Varian, France). Segmented scalp hair was treated by incubation 15 min at 80 °C in NaOH 1 M before liquid–liquid extraction with hexane/ethyl acetate (2/1, v/v). The limits of quantification (LOQ) in blood and urine were at 0.1 ng/mL for all analytes. In hair, LOQ was <5 pg/mg for MA, MDMA, MDEA and MBDB, at 14.7 pg/mg for AP and 15.7 pg/mg for MDA. Calibration curves were linear in the range 0.1–50 ng/mL in blood and urine; in the range 5–500 pg/mg for MA, MDMA, MDEA and MBDB, and 20–500 pg/mg for AP and MDA. Inter-day precisions were <13% for all analytes in all matrices. Accuracy was <20% in blood and urine at 1 and 50 ng/mL and <10% in hair at 20 and 250 pg/mg. This method was applied to the determination of MDMA in a forensic case of single administration of ecstasy to a 16-year-old female without her knowledge during a party. She suffered from hyperactivity, sweating and agitation. A first sample of urine was collected a few hours after (T + 12 h) and tested positive to amphetamines by immunoassay by a clinical laboratory. Blood and urine were sampled for forensic purposes at day 8 (D + 8) and scalp hair at day 60 (D + 60). No MDMA was detected in blood, but urine and hair were tested positive, respectively at 0.42 ng/mL and at 22 pg/mg in hair only in the segment corresponding to the period of the offence, while no MDA was detectable. This method allows the detection of MDMA up to 8 days in urine after single intake.     

Bloodstain age estimation through infrared spectroscopy and Chemometric models

The chemical profiling of bloodstains is essential to link the suspect with the crime. The current study proposed a proof-of-concept methodology for the investigation of bloodstains by utilizing advanced ATR-FTIR spectroscopy coupled with new generation chemometric methods. Current study provides encouraging data to allow discrimination between human and animal blood though with small sample size. In this study, different models for the age estimation of human bloodstains are developed from the trained data sets of 1–175 days old bloodstains. The models such as curve estimation (CE), multiple linear regression (MLR), and partial least squares regressions (PLSR) are developed to determine the best prediction model for aged human bloodstains. The obtained results on the dating of bloodstains are very encouraging and also tested for unknown samples. The maximum dating errors are observed in the curve estimation models whereas, the other models MLR, PLSR show excellent age estimation of unknown bloodstains. These models represent an error of ~3 ± 1 days and ~4 ± 1 days in actual and estimated date, respectively, which is lowest ever reported so far. The present methodology is expected to provide a valuable insight into forensic society and hence, to the law enforcement community. The present methodology can further be explored for an ideal model by including all other external variables/factors and for more longer aging time.     

Taphonomic Marks on Pig Tissue Due to Cadaveric Coleoptera Activity Under Controlled Conditions

The aim of this work was to study taphonomic marks that cadaveric coleopteran can produce under controlled conditions. To evaluate this, pig trotters were initially exposed to adults of Dermestes maculatus De Geer at 21 ± 5°C and a 12:12‐h day/night cycle. Observations were made and photographs taken every 4–5 days for 9 months. When feeding and reproducing, D. maculatus produced, in both adult and larvae stages, different types of marks such as holes, striations, scratches, and pits in several kinds of tissue such as integumental, connective, and muscular, in both their fresh and dried stages. Bite marks were also evident. The results in this study provide not only taphonomic but also biological and forensic information. This is the first time that this kind of experiment has been performed.     

Computational Approach to Identify Different Injuries by Firearms

Complications arise in the analysis of gunshot wounds to the maxillofacial region, when neither the projectile nor the gun is found at the crime scene. We simulated 5‐ and 15‐cm firing distances at a human mandible to investigate the external morphology of entrance wounds based on fire range. The ammunition models, .40‐caliber S&W, .380‐caliber, and 9 × 19‐mm Luger, were constructed with free‐form NURBS surfaces. In a dynamic simulation, projectiles were fired against mandibular body 3D model at 5 and 15 cm. All entrance wounds presented oval aspect. Maximum diameter and von Mises stress values were 16.5 mm and 50.8 MPa, both for .40‐caliber S&W fired at 5 cm. The maximum energy loss was 138.4 J for .40 S&W fired at 15 cm. In conclusion, the mandible was most affected by .40‐caliber S&W and morphological differences were observable in holes caused by different incoming projectile calibers fired at different distances.     

AGE AND ITS RELATION TO CRIME IN TAIWAN AND THE UNITED STATES: INVARIANT,OR DOES CULTURAL CONTEXT MATTER?*

Current empirical and theoretical understanding of the relation between age and crime is based almost entirely on data from the United States and a few prototypical Western societies for which age‐specific crime information across offense types is available. By using Western databases, Hirschi and Gottfredson (1983) projected that the age distribution of crime is always and everywhere robustly right‐skewed (i.e., sharp adolescent peak)—a thesis that is both contested and widely accepted in criminology and social science writings. In the study described here, we tested this age–crime invariance thesis by comparing age–crime patterns in Taiwan (a non‐Western Chinese society) with those in the United States. In light of Taiwan's collectivist culture versus the U.S. individualist gestalt, we anticipated more divergence than homogeneity in their age–crime schedules. Our findings show robust divergence in Taiwan's age–crime patterns compared with U.S. patterns and the reverted J‐shaped norm projected by Hirschi and Gottfredson. Implications for research and theory on the age–crime relation and for studying human development or life‐course topics more broadly are discussed.     

Accumulation of explosives in hair--Part 3: Binding site study

This study extends previous work on the sorption of explosives to the hair matrix. Specifically, we have studied the interaction of 2,4,6-trinitrotoluene (TNT) and triacetone triperoxide (TATP) as a function of chemical pretreatment with acetonitrile, neutral and alkaline hydrogen peroxide, methanolic KOH and potassium permanganate, and the morphological changes that accompany these treatments. While differences in vapor pressure can account for quantitative differences between TNT and TATP sorption, both are markedly affected by the chemical rinses. Examination of the hair surface shows different degrees of smoothening following rinsing, suggesting that the attachment to hair is largely a surface phenomenon involving the 18-methyleicosanoic acid lipid layer. Density functional theory calculations were employed to explore possible nucleation sites of TATP microcrystals on the hair. We conclude that some of the sites on melanin granular surfaces may support nucleation of TATP microcrystals. Moreover, the calculations support the experimental finding that dark hair adsorbs explosives better than light hair.     

Blood and sperm traces on human hair. A study on preservation and detection after 3-month outdoor exposure

Hair can retain important biological traces for forensic investigations. Forensic scientists are used to looking for such traces on clothing and skin of victims, however, when decomposition kicks in and all that remains of the victims is the skeleton, hair may be the only tissue representing the surface of the body at the time of a crime on which biological traces of an aggressor may have been left and still be detectable. Given the lack of research on this topic, this pilot study aims to assess the capacity of hair to retain semen and blood in hair, and the possibility to detect these fluids with well-known techniques and to obtain a useful genetic profile even when exposed to environmental conditions (Open Natural Environment (woods), Open Man Made Environment (urban)) for three months.Results showed that both traces were always visible and detectable with almost all techniques in the Control Environment, while in the two open environments some difficulties arose. However, biomolecular analysis was effective up to three months on both fluids in the Natural Environment and up to two months and one week respectively on blood and semen in the Man Made Environment. The Combur Test, OBTI, and Luminol were effective on blood up to three months in both environments while Sperm-HY-Liter and observation of cellular components were effective on semen up to at least 1 month and PSA testing was positive up to 1 week in both environments.The present work can be considered an encouraging starting point for the analysis of biological traces on hair in forensic contexts, regardless of the PMI, since blood and semen related to a crime may survive.