Angular Determination of Toolmarks Using a Computer‐Generated Virtual Tool

A blind study to determine whether virtual toolmarks created using a computer could be used to identify and characterize angle of incidence of physical toolmarks was conducted. Six sequentially manufactured screwdriver tips and one random screwdriver were used to create toolmarks at various angles. An apparatus controlled tool angle. Resultant toolmarks were randomly coded and sent to the researchers, who scanned both tips and toolmarks using an optical profilometer to obtain 3D topography data. Developed software was used to create virtual marks based on the tool topography data. Virtual marks generated at angles from 30 to 85° (5° increments) were compared to physical toolmarks using a statistical algorithm. Twenty of twenty toolmarks were correctly identified by the algorithm. On average, the algorithm misidentified the correct angle of incidence by ?6.12°. This study presents the results, their significance, and offers reasons for the average angular misidentification.     

Bolt Cutter Blade's Imprint in Toolmarks Examination

Bolt cutters are known as cutting tools which are used for cutting hard objects and materials, such as padlocks and bars. Bolt cutter blades leave their imprint on the cut objects. When receiving a cut object from a crime scene, forensic toolmarks examiners can determine whether the suspected cutting tool was used in a specific crime or not based on class characteristic marks and individual marks that the bolt cutter blades leave on the cut object. The paper presents preliminary results of a study on ten bolt cutters and suggests a quick preliminary examination—the comparison between the blade thickness and the width of the imprint left by the tool on the cut object. Based on the comparison result, if there is not a match, the examiner can eliminate the feasibility of the use of the suspected cutting tool in a specific crime. This examination simplifies and accelerates the comparison procedure.     

Quantitative Statistics and Identification of Tool‐Marks

This study was designed to establish a feature identification method of tool‐mark 2D data. A uniform local binary pattern histogram operator was developed to extract the tool‐mark features, and the random forest algorithm was adopted to identify these. The presented method was used to conduct five groups of experiments with a 2D dataset of known matched and nonmatched tool‐marks made by bolt clippers, cutting pliers, and screwdrivers. The experimental results show that the proposed method achieved a high rate of identification of the tool‐mark samples generated under identical conditions. The proposed method effectively overcomes the disadvantage of unstable illumination of 2D tool‐mark image data and avoids the difficulty in mark inspection caused by manually preset parameters in the existing methods, thus reducing the uncertainty of inspected results.     

Development of a Mobile Toolmark Characterization/Comparison System

Since the development of the striagraph, various attempts have been made to enhance forensic investigation through the use of measuring and imaging equipment. This study describes the development of a prototype system employing an easy‐to‐use software interface designed to provide forensic examiners with the ability to measure topography of a toolmarked surface and then conduct various comparisons using a statistical algorithm. Acquisition of the data is carried out using a portable 3D optical profilometer, and comparison of the resulting data files is made using software named “MANTIS” (Mark and Tool Inspection Suite). The system has been tested on laboratory‐produced markings that include fully striated marks (e.g., screwdriver markings), quasistriated markings produced by shear‐cut pliers, impression marks left by chisels, rifling marks on bullets, and cut marks produced by knives. Using the system, an examiner has the potential to (i) visually compare two toolmarked surfaces in a manner similar to a comparison microscope and (ii) use the quantitative information embedded within the acquired data to obtain an objective statistical comparison of the data files. This study shows that, based on the results from laboratory samples, the system has great potential for aiding examiners in conducting comparisons of toolmarks.     

Optimization of a Statistical Algorithm for Objective Comparison of Toolmarks

Due to historical legal challenges, there is a driving force for the development of objective methods of forensic toolmark identification. This study utilizes an algorithm to separate matching and nonmatching shear cut toolmarks created using fifty sequentially manufactured pliers. Unlike previously analyzed striated screwdriver marks, shear cut marks contain discontinuous groups of striations, posing a more difficult test of algorithm applicability. The algorithm compares correlation between optical 3D toolmark topography data, producing a Wilcoxon rank sum test statistic. Relative magnitude of this metric separates the matching and nonmatching toolmarks. Results show a high degree of statistical separation between matching and nonmatching distributions. Further separation is achieved with optimized input parameters and implementation of a “leash” preventing a previous source of outliers—however complete statistical separation was not achieved. This paper represents further development of objective methods of toolmark identification and further validation of the assumption that toolmarks are identifiably unique.     

An Improved Version of a Tool Mark Comparison Algorithm

Chumbley et al. (2010) described a statistically based algorithm for comparing pairs of tool marks. They presented empirical evidence that the algorithm produces well‐separated similarity score values for “matching” and “non‐matching” pairs of tool marks. However, the algorithm has two substantial weaknesses. First, it is “uncalibrated” in the sense that error rates can be determined only through empirical investigation. Second, it relies on a randomized test and can lead to different similarity scores when the algorithm is repeatedly applied to the same pair of tool marks. We present an improved version of the procedure, which eliminates the randomized scores and yields more consistent and predictable error rate control. This is accomplished by replacement of a random sampling step from the original algorithm with a deterministic process. We demonstrate the improved algorithm and compare its performance to the original by applying to known “matching” and “non‐matching” pairs of tool marks.     

Friction Marks of Stabbing Tools in Tires

When receiving a stabbed tire for examination, forensic toolmark examiners can determine whether a suspect tool was used in a specific crime based on class-characteristics and individual-characteristics marks that have been left by the tool on the tire. This study discusses friction marks and their forensic value during the examination of a punctured tire. The term friction mark refers to the noticeable mark around the penetration area on a tire's surface. Tires designed to create high friction when contacting a road. Due to this design, friction is created between the stabbing tool shank and the sides of the hole. As a result of this friction, the shank of the stabbing tool wears the outer layer of tire around the hole. This leaves a friction mark whose general shape reflects the cross-sectional shape of the stabbing tool’s shank. This phenomenon was observed and named by Locke (7) in his evaluation of tire puncture marks with knives. This article demonstrates the same phenomenon with other types of stabbing tools. Test stabs were produced with different tools representing a variety of cross-sectional shapes of shanks, and the resulting friction marks were photo-documented and discussed. Correlations between the various cross-sectional shapes and their corresponding friction marks are shown. Based on friction mark examination, the examiner: (i) can infer suspect tool shank cross-sectional shape with the evaluation of the friction mark shape and (ii) can deduce the maximum dimensions of the shank. This examination simplifies and accelerates the forensic comparison procedure and the investigation time.     

Comparison of Dimensional Accuracies Using Two Elastomeric Impression Materials in Casting Three‐dimensional Tool Marks

The purpose of this study was to evaluate two types of impression materials which were frequently used for casting three‐dimensional tool marks in China, namely (i) dental impression material and (ii) special elastomeric impression material for tool mark casting. The two different elastomeric impression materials were compared under equal conditions. The parameters measured were dimensional accuracies, the number of air bubbles, the ease of use, and the sharpness and quality of the individual characteristics present on casts. The results showed that dental impression material had the advantage of special elastomeric impression material in casting tool marks in crime scenes; hence, it combined ease of use, dimensional accuracy, sharpness and high quality.     

Human Identification Using Automatic and Semi‐Automatically Detected Facial Marks

Continuing advancements in the field of digital cameras and surveillance imaging devices have led law enforcement and intelligence agencies to use analysis of images and videos for the investigation and prosecution of crime. When determining identity from photographic evidence, forensic analysts perform comparison of visible facial features manually, which is inefficient. In this study, we will address research efforts to use facial marks as biometric signatures to distinguish between individuals. We propose two systems to assist forensic analysts during photographic comparison: an improved multiscale facial mark system in which facial marks are detected automatically, and a semi‐automatic facial mark system that integrates human knowledge within the improved multiscale facial mark system. Experiment results employ a high‐resolution time‐elapsed dataset acquired at the University of Notre Dame between 2009 and 2011. The results indicate that the geometric distributions of facial mark patterns can be used to distinguish between individuals.     

Fatality of 33‐Year‐Old Man Involving Kratom Toxicity

Kratom is an herbal product commonly used for its effects which are similar to opioids and stimulants. Few studies demonstrate the dangers and lethality of Kratom, and most fatalities from Kratom involve other abused substances. In the current case report, a 33‐year‐old white man with a known history of opioid abuse and mental illnesses was found unresponsive in his basement with no obvious signs of trauma. After resuscitative efforts, he was pronounced dead and taken for autopsy evaluation. Blood from the inferior vena cava was analyzed for common abused substances. The laboratory toxicology work‐up revealed positive findings of caffeine, cotinine, and naloxone with low levels of Δ‐9 tetrahydrocannabinol. However, a marked level of mitragynine at 1.9 mg/L was observed, the highest reported to date. Given the facts and evidence, the medical examiner certified the cause of death as “mitragynine toxicity” and the manner of death was classified as an “accident.”     

Delirium Due to Intoxication from the Novel Synthetic Tryptamine 5‐MeO‐DALT

Synthetic tryptamines have gained popularity for their hallucinogenic properties, unscheduled status, and availability from “head shops” and through the internet. Here, we present a case of synthetic tryptamine‐induced delirium secondary to 5‐MeO‐DALT ingestion in a previously healthy young male. 5‐MeO‐DALT led to the hospitalization of our patient after ingestion of a standard dose, presenting with extreme agitation, tachycardia, diaphoresis, and combativeness leading to physical restraint and intravenous sedation. A search of PubMed, Ovid, and Google Scholar for keywords of “5‐MeO‐DALT,” “5‐methoxy‐N,N‐diallyltryptamine,” or “Lucy‐N‐Nate” found no case reports or clinical articles in the literature. Rapid emergence and commercialization of this novel synthetic tryptamine 5‐MeO‐DALT points to the importance of health care and forensic professionals keeping abreast of the latest drugs of abuse and their clinical features. The authors hope this report leads the way in disseminating the potential risks associated with unscheduled and unregulated substances, synthetic tryptamines such as 5‐MeO‐DALT in particular.     

Virtual Tool Mark Generation for Efficient Striation Analysis,

This study introduces a tool mark analysis approach based upon 3D scans of screwdriver tip and marked plate surfaces at the micrometer scale from an optical microscope. An open‐source 3D graphics software package is utilized to simulate the marking process as the projection of the tip's geometry in the direction of tool travel. The edge of this projection becomes a virtual tool mark that is compared to cross‐sections of the marked plate geometry using the statistical likelihood algorithm introduced by Chumbley et al. In a study with both sides of six screwdriver tips and 34 corresponding marks, the method distinguished known matches from known nonmatches with zero false‐positive matches and two false‐negative matches. For matches, it could predict the correct marking angle within ±5–10°. Individual comparisons could be made in seconds on a desktop computer, suggesting that the method could save time for examiners.     

A Fully Automatic Method for Comparing Cartridge Case Images,

When a gun is fired, it leaves marks on cartridge cases that are thought to be unique to the gun. In current practice, firearms examiners inspect cartridge cases for “sufficient agreement,” in which case they conclude that they come from the same gun, testifying in courts as such. A 2016 President's Council of Advisors on Science and Technology report questioned the scientific validity of such analysis (President's Committee of Advisors on Science and Technology, Washington, DC, Executive Office of the President). One recommendation was to convert firearms analysis to an objective method. We propose a fully automated, open‐source method for comparing breechface marks on cartridge cases using 2D optical images. We improve on existing methodology by automating the selection of marks, and removing the effects of circular symmetry. We propose an empirical computation of a “random match probability” given a known database, which can be used to quantify the weight of evidence. We demonstrate an improvement in accuracy on images from controlled test fires.     

Effectiveness of comparison overlays generated with DentalPrint software in bite mark analysis

Validation studies of the new DentalPrint software were carried out with experimental bite marks in pigskin. The bite marks were digitally photographed according to the ABFO guidelines for evidence collection. Dental casts used in the experiment were scanned in 3D and 2D, and comparison overlays were generated using DentalPrint and Adobe Photoshop software, respectively. Digitized photographs of the experimental bite marks and the biting edges obtained in the overlays were compared by two different examiners to analyze the impact of training and experience with the two methods. Receiver operating characteristic (ROC) analysis, sensitivity, specificity, and 95% confidence intervals for each cutoff point were calculated. The expert examiner using DentalPrint obtained the best results, with an area under the ROC curve of 0.76 (SE=0.057; CI at 95%=0.652-0.876). Fairly high specificity values were found for DentalPrint, and the best results were obtained for the cutoff value that discriminated between the examiner's response "biter" and the rest of the possible (specificity 97.9%, CI at 95%=93.2%-99.6%). Therefore, the results presented here indicate that DentalPrint is a useful, accurate tool for forensic purposes, although further research on the comparison process is needed to enhance the validity of bite mark analysis.     

Characterization of In Vitro Metabolites of CP 47,497, a Synthetic Cannabinoid,in Human Liver Microsomes by LC‐MS/MS

CP 47,497, a potent cannabinoid receptor type 1 agonist, is the main active ingredient in the herbal mixture “Spice” sold in European countries. The illegal use of “Spice” for its psychoactive effects has become a social issue. In this study, the in vitro metabolism of CP 47,497 was investigated in human liver microsomes to characterize the metabolic fate of CP 47,497. CP 47,497 was incubated with human liver microsomes, and the reaction mixture was analyzed using liquid chromatography‐tandem mass spectrometry. A total of eight metabolites were detected in human liver microsomes and structurally characterized based on mass spectral data. The main metabolic pathways involved hydroxylations or oxygenations. The identified metabolites were mono‐oxygenated metabolites (M1 and M4), mono‐hydroxylated metabolites (M3, M5, M6, M7, and M8), and a di‐oxygenated metabolite (M2). The detection of these metabolites could confirm the presence of CP 47,497 in biological samples; therefore, collectively, they would be excellent indicators of “Spice” drug abuse.     

Experimental Study of Bite Mark Injuries by Digital Analysis

Abstract: This study was based on a morphometric analysis of bite marks starting from the quantitative definition of the anterior teeth by the geometric acquisition of the “injuries,” using bite marks impressed on pig skin and plastic. Each mark was photographed and acquired. A dedicated program automatically supplied the values of the shape factors and the areas of the pattern geometric figures. The values obtained for the homologous samples were compared to the heterologous values. Statistical comparison was made of the sets by linear regression, determining the correlation coefficient and the determination coefficient for each value. Results showed only 4.8% and 2% of overlap between homologous and heterologous values. This study was carried out in attempting to quantitatively define the anterior teeth of the human dentition and the procedure described and the results obtained support the advantage of morphometric studies and computer‐aided programs in this study of bite marks.     

Classification of Opium by UPLC‐Q‐TOF Analysis of Principal and Minor Alkaloids

Opium is the raw material for the production of heroin, and the characterization of opium seizures through laboratory analysis is a valuable tool for law enforcement agencies to trace clandestine opium production and trafficking. In this work, a method for opium profiling based on the relative content of five principal and 14 minor opium alkaloids was developed and validated. UPLC‐Q‐TOF was adopted in alkaloid analysis for its high selectivity and sensitivity, which facilitated the sample preparation and testing. The authentic sample set consisted of 100 “Myanmar” and 45 “Afghanistan” opium seizures; based on the data set of the 19 alkaloid variables in them, a partial least squares discriminant analysis classification model was successfully achieved. Minor alkaloids were found to be vitally important for opium profiling, although combined use of both principal and minor alkaloids resulted in the best geographical classification result. The developed method realized a simple and accurate way to differentiate opium from Myanmar and Afghanistan, which may find wide application in forensic laboratories.     

Optical Characterization of Some Modern “Eco‐Friendly” Fibers*

Abstract: Fibers that are termed “eco‐friendly” or “biodegradable” by manufacturers are increasingly being used in textile products such as apparel and carpeting to appeal to the ever more environmentally aware public. As such, these modern fibers are expected to begin showing up more often in forensic casework, and it is important that the forensic examiner recognize them. This study employed polarized light microscopy (PLM) and Fourier transform infrared (FTIR) microspectroscopy to characterize selected fibers of azlon, polylactic acid (PLA), cellulose composites of alginate or chitin, and bamboo (viscose rayon). Fiber cross‐sections, refractive indices, melting points, solubilities, and FTIR measurements were conducted. Results indicate that the azlons and PLA fibers are easily distinguishable from other textile fibers by their optical and chemical properties. The cellulose composites show only small differences in comparison with other cellulose‐based fibers, while bamboo viscose rayon is indistinguishable from normal viscose rayon.     

Self‐harm Risk Among Adolescents and the Phenomenon of the “Blue Whale Challenge”: Case Series and Review of the Literature

The “Blue Whale Challenge” is a dangerous Internet phenomenon. As per media reports, it involves a series of life‐threatening tasks imposed by a “curator” to “players,” who must fulfill the whole list, and it ends with the suicide of the player. The authors report the data of five suspected cases of “Blue Whales” managed from January 2016 to December 2017 by the staff of a unit (the “Bambi Unit” of the Pediatric Hospital “Regina Margherita” of Turin, Italy) that is dedicated to the evaluation of suspected abused children. Then, they analyzed this data in the light of the literature regarding self‐harm. This comparison highlights the role of the Internet in the spreading of self‐harm behavior among vulnerable adolescents who are characterized by epidemiological, psychological, psychiatric, social, and cultural risk factors. In conclusion, the authors suggest a multidisciplinary and specialized approach in the evaluation of adolescents who committed self‐harm activities.     

The Biggest “Have” of Them All: Wal‐Mart and Its Litigation Outcomes in Slip‐and‐Fall Cases

Scholars have theorized that resource‐rich litigants known as the “haves” tend to succeed disproportionately in litigation when the adverse party is a “have‐not.” The traditional theory suggests that haves are able to use their wealth to secure better attorney representation and can use their frequent experience in litigation to tip the scales of justice in their favor, particularly when faced with “one‐shotters” whose involvement in litigation is infrequent. A remaining question, however, is whether some haves fare better than other similarly situated haves. Specifically, this article posits that the litigation strategy used by the defendant may also play a role in litigation outcomes. Companies that tenaciously fight claims that, in the short term, would be cheaper to settle might discourage otherwise valid claims in the future from being filed out of fear that the litigation will be a protracted battle. This article examines Wal‐Mart Stores, Inc. (Wal‐Mart)—the largest revenue‐generating company in the United States—to explore whether it fares better than other resource‐rich defendants. Wal‐Mart in particular has a reputation against settling cases and thus is an excellent vehicle to investigate this hypothesis. Appellate cases in an eleven‐year period involving slip‐and‐fall litigation were compiled, and the results show that Wal‐Mart did win at a higher rate than other defendants. Although more research is needed to explore fully the effect of litigation strategy on win–loss rates, this sample of cases demonstrates that Wal‐Mart is a more effective and victorious litigant.