Development of a Dundee Ground Truth imaging protocol for recording indoor crime scenes to facilitate virtual reality reconstruction

Early and accurate visualisation of a crime scene is highly desirable such that a rapid, agile, and informed decision-making process can be undertaken by an investigative team. We present a new standard operating procedure for imaging an indoor scene using DSLR cameras conventionally used by crime scene investigators and examiners. The standard operating procedure (SOP) enables the systematic photography of indoor spaces in such a way that the Structure from Motion (SfM) photogrammetry technique can be implemented, allowing the scene to be recreated in Virtual Reality (VR). To demonstrate the method’s validity, we compare two VR-rendered representations of an example scene using (a) photographs taken by an experienced crime scene examiner using a conventional photographic method and (b) photographs taken by a novice photographer following the developed SOP.     

Detection of medical examiner cases from review of cremation requests

Title 9, Chapter 19, Article 3 of the Arizona Administrative Code requires all bodies that are to be cremated must have the death certificate reviewed by a county medical examiner. In Tucson, AZ, and surrounding Pima County, all cremation requests are submitted to the Forensic Science Center, where the death certificates are reviewed by one of 5 board-certified forensic pathologists. In 2002, there were 5557 cremation requests, and in 2003 there were 5662 cremation requests. Of these requests, 670 (12.1%) and 447 (7.9%) death certificates were flagged for further investigation in 2002 and 2003, respectively. Eventually, 47 cases (0.8% of total, 7.0% of flagged cases) were accepted as medical examiner cases in 2002, and 43 cases (0.8% of total, 9.6% of flagged cases) were accepted as medical examiner cases in 2003. In 2002, the majority of cases were handled as a records review; however, 4 cases were brought in for autopsy and 1 was certified after an external examination only. In 2003, all cases were certified via a records review. The manner of death in all but 3 of these deaths was certified as accident, with complications of remote trauma being the most common proximate cause of death. The 3 most common injuries were complications of fractured pelvis or femur (15 in 2002, 22 in 2003), head injury due to fall (18 in 2002, 8 in 2003), and complications of remote motor vehicle accident (3 in 2002, 6 in 2003). The other 3 deaths included 2 homicides, 1 in each year, and 1 suicide in 2003.     

Manufacturing processes for athletic shoe outsoles and their significance in the examination of footwear impression evidence

The most common methods of manufacturing athletic shoe outsoles are given and how each method can influence the examination of footwear impression evidence. Several processes for manufacturing athletic shoe outsoles are described. Significant factors of each process that are relevant to the examination of footwear impressions are explained. Some manufacturing processes result in distinguishing random characteristics which can assist in the identification of a shoe sole, even when new. These characteristics, together with the traditionally observed wear patterns and random cuts on the shoe outsoles, enable the examiner a stronger basis for expert opinion.     

The Patent Examiner Sweepstakes

This article presents evidence that patent value varies with random examiner assignment at the U.S. Patent Office. Prior work analyzed firm growth as a function of review by “easy” examiners who grant patents at a high rate. The current research looks past whether a patent is granted and instead focuses on how assignment to an “easy” or “hard” examiner influences the attributes of resultant patents. Focusing on their propensities to reject applications on novelty or obviousness grounds, analysis finds that patents issued by lenient examiners tend to be broader in scope, are more valuable to their owners, and elicit a larger stock market response when granted. Further analysis quantifies the level of variation (“noise”) among examiners. This inquiry finds that the noise level in issuing novelty rejections decreases with examiner experience, while variation among examiners issuing obviousness rejections actually increases with experience. A third line of investigation presents evidence that “stricter” examiners disproportionately reach the correct examination relative to more lenient counterparts. This conclusion is supported by “twin application” analysis comparing outcomes of related U.S. and European applications. Consistent with the literature using this method, the European Patent Office's outcome is considered the “gold standard” for examination, and thus, its decision to grant or deny is assumed correct.     

Identification of the unidentified deceased: turnaround times, methods, and demographics in Fulton County, Georgia

CONTEXT: Multiple methods may be employed in an attempt to identify deceased individuals who are unidentified when reported to the medical examiner or coroner. The success and turnaround times of various methods differ. OBJECTIVE: To determine the number of deaths initially involving unidentified individuals, their demographics, the methods used and turnaround times for cases in which identification was successful and the portion of cases that remain unidentified for significant periods of time. DESIGN, SETTING, AND PARTICIPANTS: Retrospective case review of all decedents who were initially unidentified when death was reported to the Fulton County Medical Examiner in Atlanta, Georgia, during a 1-year period between May 2003 and May 2004. MAIN OUTCOME MEASURES: Rate per 1000 deaths which involved an unidentified decedent, tabulation of methods used to make identifications, and rate of cases remaining unidentified. RESULTS: Of 2279 deaths reported to the office, 100 were originally unidentified, resulting in a rate of 44 unidentified decedents per 1000 deaths reported. Those who remained unidentified involved 6 cases, resulting in a "cold case" rate of 2.6 per 1000 deaths. Seventy-eight percent were identified within 2 days, and the most common successful methods were visual identification (52%) and fingerprints (31%). Dental (10%), x-ray (4%), and other methods (6%) were least commonly used. Of the 94 persons identified, all identifications occurred within 29 days. DNA procedures were not needed in most cases, and in the few cases where such tests were needed, results were either unavailable or failed to show a match with known samples. CONCLUSIONS: The majority of unidentified deceased individuals were identified within 2 days, with visual verification or fingerprints accounting for about 83% of methods successfully employed. The medical examiner noted a rate of 44 unidentified deceased persons per 1000 death reports, with an ultimate "cold case" (long-term unidentified) rate of about 2.6 cases per 1000 death reports. These data may be useful in developing office policy and procedure regarding the procedural and temporal aspects of investigations centered on achieving identification and making dispositions of unidentified deceased bodies.     

The effects of latent print processing on questioned documents produced by office machine systems utilizing inkjet technology and toner

Counterfeiting of currency and identity documents, death threats, illegitimate business transactions, and terrorist-related activities are some examples of the types of crimes that often involve documents produced from printers and copiers. Although standard protocol typically requires a questioned document (QD) examination prior to latent print (LP) processing, occasionally, items of evidence may be submitted for a QD examination following the application of a series chemicals utilized in the development of latent fingerprints. In such cases, the forensic examiner must take into account any previous treatments prior to initiating an examination on documents produced with a printer or copier. This study was devised to examine the effects of a latent print development technique [ninhydrin, physical developer, and a bleach enhancer] on the physical and chemical examination of documents produced from copiers and printers.     

Sudden infant death syndrome: diagnostic practices and investigative policies, 2004

Using a 2004 population-based survey of all US medical examiner and coroner offices, we examined the characteristics of offices accepting an infant death case and calculated the percentage of offices that had death scene investigation or autopsy policies for the investigation of sudden unexpected infant death (SUID). We also calculated the percentage of offices that used and did not use sudden infant death syndrome (SIDS) as a cause of death, and we compared differences in characteristics among those offices.Of medical examiner and coroner offices, 52% did not report an infant death in 2004. Of the 7957 infant deaths reported, 43% occurred in jurisdictions that experienced 1 or 2 infant deaths. Of the offices that used SIDS as a classification, 34% did not have policies for conducting death scene investigations and autopsies for SUID. At least 5% of offices that reported an infant death did not use SIDS as a cause of death classification. These findings have important implications for understanding recent trends in SIDS and SUID. Supporting the implementation of national standards for investigating and certifying infant deaths could provide guidelines for consistent practices in medical examiner and coroner offices.     

National Association of Medical Examiners position paper on the medical examiner release of organs and tissues for transplantation

The medical examiner community plays a key role in the organ and tissue procurement process for transplantation. Since many, if not most, potential organ or tissue donors fall under medicolegal jurisdiction, the medical examiner bears responsibility to authorize or deny the procurement of organs or tissues on a case-by-case basis. This responsibility engenders a basic dichotomy for the medical examiner's decision-making process. In cases falling under his/her jurisdiction, the medical examiner must balance the medicolegal responsibility centered on the decedent with the societal responsibility to respect the wishes of the decedent and/or next of kin to help living patients. Much has been written on this complex issue in both the forensic pathology and the transplantation literature. Several studies and surveys of medical examiner practices, as well as suggested protocols for handling certain types of cases, are available for reference when concerns arise that procurement may potentially hinder medicolegal death investigation. It is the position of the National Association of Medical Examiners (NAME) that the procurement of organs and/or tissues for transplantation can be accomplished in virtually all cases, without detriment to evidence collection, postmortem examination, determination of cause and manner of death, or the conducting of criminal or civil legal proceedings. The purpose of this position paper is to review the available data, the arguments for and against medical examiner release, and to encourage the release of organs and tissues in all but the rarest of circumstances.     

Cognitive biases in the peer review of bullet and cartridge case comparison casework: A field study

ObjectiveForensic judgments and their peer review are often the result of human assessment and are thus subjective and prone to bias. This study examined whether bias affects forensic peer review.HypothesesWe hypothesized that the probability of disagreement between two forensic examiners about the proposed conclusion would be higher with “blind” peer review (reviewer saw only the first examiner’s comparison photos) than with “non-blind” peer review (reviewer also saw the first examiner’s interpretation and proposed conclusion). We also hypothesized that examiners with a higher perceived professional status would have a larger effect on the reported conclusion than examiners with a lower status.MethodWe acquired data during a non-blind and a blind peer review procedure in a naturalistic, covert study with eight examiners (3–26 years of experience). We acquired 97 conclusions of bullet and cartridge case comparisons in the blind and 471 in the non-blind peer review procedure.ResultsThe odds of disagreement between examiners about the evidential strength of a comparison were approximately five times larger (95%-CI [3.06, 8.50]) in the blind than in the non-blind procedure, with disagreement about 42.3% and 12.5% of the proposed conclusions, respectively. Also, the odds that their proposed conclusion was reported as the final conclusion were approximately 2.5 higher for the higher-status examiners than for lower-status examiners.ConclusionsOur results support both the hypothesis that bias occurs during non-blind forensic peer review and the hypothesis that higher-status examiners determine the outcome of a discussion more than lower-status examiners. We conclude that blind peer review may reduce the probability of bias and that status effects have an impact on the peer reviewing process.     

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.     

A mobile system for postmortem genital examinations with colposcopy: SART-TO-GO

The interpretation of genital findings in the deceased is a vital and timely issue. A paucity of information exists on the nature and appearance of the anogenital tissues in the postmortem interval. The traditional postmortem genital examination consists of gross visualization, which may preclude detection of the subtler trauma that usually constitutes injury in sexual assault. The mobile system grew out of a need to bring the examiner to the patient, e.g., in jurisdictions that lack a centralized morgue. The theoretical framework of the methodology lies in the sexual activity that culminates in the death of the sexual homicide victim. This sequential methodology was based on the Sexual Assault Response Team (SART) model, with adaptation to the autopsy milieu. Colposcopy is well-established for the medical-legal investigation of living sexual assault victims. During the author's initial rape-homicide examinations, only gross visualization was available. It soon became apparent that a system that facilitated detailed scrutiny of the anogenital tissues at various postmortem intervals was needed. Colposcopy was selected as the examination method because of its magnification, photodocumentation, and peer review potential. The sequential protocol was developed and refined during an ongoing accumulation of baseline cases. The role of the forensic nurse examiner is described within a defined scope of expertise and as a collaborative member of the homicide investigative team.     

Practical GC/MS analysis of oxidation dye components in hair fiber as a forensic investigative procedure

The purpose of this study was to improve the reliability of discrimination (or identification) of dyed hair by analyzing chemical substances present in the hair, as an addition to the conventional macroscopical and microscopical examinations and ABO blood group examination. Oxidation hair-dye components such as p-phenylenediamine (PPDA), toluylene-2,5-diamine (T-2,5-DA), o-aminophenol (OAP), m-aminophenol (MAP), p-aminophenol (PAP) and p-amino-o-cresol (PAOC) were selected as the object of study. After alkaline-digestion, hair samples were adjusted to a pH of 12.6 to 12.8, and applied onto an Extrelut column. After 15 min, the components were simultaneously extracted and derivatized with n-hexane including 1% heptafluoro-n-butyryl (HFB) chloride. Their HFB derivatives within a condensed sample were diluted in ethyl acetate, and analyzed by gas chromatography-mass spectrometry (GC-MS) with full mass scanning or selected ion monitoring. For estimating their levels, 2,4,6-trimethylaniline was used as the internal standard. Standard curves obtained by preparing a 5 cm segment of control hair spiked with authentic substances were linear, ranging from 0.1 to 4.0 micrograms for PPDA and T-2,5-DA, and from 0.01 to 0.4 microgram for OAP, MAP, PAP and PAOC. The coefficient of variation of inter-day precisions (each n = 4) was below 16% for PPDA, below 20% for OAP and PAP and below 24% for T-2,5-DA, MAP and PAOC. These components were detectable even at 6 ng for PPDA, T-2,5-DA, MAP and PAP, 8 ng for OAP, and 4 ng for PAOC. Recovery percents using this procedure ranged from 54 to 86%. By using actual dyed hair samples this method was shown to provide high sensitivity for accurate detection.     

Postmortem Computed Tomography in Firearm Homicides: A Retrospective Case Series,

Postmortem computed tomography (PMCT) is integrated into the evaluation of decedents in several American medical examiner offices and medicolegal death investigative centers in many other countries. We retrospectively investigated the value of PMCT in a series of firearm homicide cases from a statewide centralized medical examiner’s office that occurred during 2016. Autopsies were performed or supervised by board-certified forensic pathologists who reviewed the PMCT scans prior to autopsy. PMCT scans were re-evaluated by a forensic radiologist blinded to the autopsy findings and scored by body region (head–neck, thoracoabdominal, and extremities). Injury discrepancies were scored using a modified Goldman classification and analyzed with McNemar’s test. We included 60 males and 20 females (median age 31 years, range 3–73). Based on PMCT, 56 (79.1%) cases had injuries relevant to the cause of death in a single body region (24 head–neck region, 32 thoracoabdominal region). Out of these 56 cases, 9 had a missed major diagnosis by PMCT outside that region, including 6 extremity injuries visible during standard external examination. Yet all had evident lethal firearm injury. We showed that PMCT identifies major firearm injuries in homicide victims and excludes injuries related to the cause of death in other regions when a single body region is injured. Although PMCT has a known limited sensitivity for soft tissue and vascular pathology, it can be combined with external examination to potentially reduce or focus dissections in some of these cases depending on the circumstances and medicolegal needs.     

Factors Influencing the Filing of Complaints,Their Investigation,and Subsequent Legal Judgment in Cases of Sexual Assault

In Geneva, examination of victims of sexual assault is performed by a gynecologist and a medical examiner. 48% of the victims file a complaint and we wanted to investigate the factors leading to file a complaint, those leading the Prosecutor to go to trial, and those influencing a conviction. Between 2006 and 2012, 676 victims of sexual assault were investigated (averaged age 26 year, mean 22). Information on injuries, perpetrators, and circumstances of the assault was collected and analyzed. The attacker being the ex‐spouse or a friend and the presence of semen were factors leading to file a complaint. The assailant being a family member or ex‐spouse and the presence of genital/anal lesions were factors influencing the Prosecutor. The presence of nongenital lesions, the assailant being known by the victim, influenced conviction. This study shows that the medical examiner plays a vital role in the investigation of cases of sexual assault.     

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.     

Cognitive and contextual influences in determination of latent fingerprint suitability for identification judgments

We examined forensic fingerprint examiners' suitability determinations of latent fingerprints comparing situations in which the latent is assessed solo (in isolation) versus situations in which it is presented alongside a comparison (matching or non-matching) exemplar print. The presence of a non-matching comparison exemplar led examiners to be more inclined to draw the conclusion that the latent was suitable for comparison compared to when the latent was presented solo. This effect persisted even when the latent presented was highly unsuitable for comparison. The presence of a matching comparison exemplar led examiners to be less likely to decide that the latent was suitable and more likely to decide the latent was questionable compared to solo analysis. This effect persisted even when the latent presented was highly suitable, suggesting a strong main effect. Knowledge of another examiner's previous determination that the latent was unsuitable was found to increase the likelihood that the examiner would conclude that the latent was unsuitable. However, knowledge of a previous “suitable” determination by another examiner did not increase the likelihood of a “suitable” conclusion by examiners. The finding that effects were weaker, although not entirely removed, in those with IAI certification suggests that training may be an appropriate route for reducing the effect of contextual influence and bias in suitability determinations. It was also shown that latent prints that were previously classed as "unsuitable" in a non-biasing context, continued to be judged to be "unsuitable" in a strongly biasing context (a major case in which a previous examiner was purported to have made an Individualization).     

Automation of a screening polygraph test increases accuracy

Abstract

The present study examined the effects of automating the Relevant–Irrelevant (RI) psychophysiological detection of deception test within a mock-screening paradigm. Eighty participants, recruited from the local community, took part in the study. Experimental design was a 2 (truthful/deceptive) by 2 (human/automation) factorial. Participants in the deceptive conditions attempted deception on two items of an employment application. Examinations conducted with the automated polygraph examination were significantly more accurate than examinations conducted by the human polygraph examiner. Statistical analyses revealed different patterns of physiological responses to deceptive items depending upon the automation condition. Those results have potentially interesting theoretical implications. The results of the present study are clearly supportive of additional efforts to develop a field application of an automated polygraph examination.     

Sudden infant death syndrome risk factors with regards to sleep position, sleep surface, and co-sleeping

We present a study of 102 Sudden Infant Death Syndrome (SIDS) deaths using a retrospective review of medical examiner autopsy reports. The prevalence of sleep related risk factors with regards to sleep surface, sleep position, and co-sleeping were determined in a population of infants less than 1-year-old. Of the 102 SIDS deaths, 67 (65.7%) were not in a crib, 63 (61.8%) were prone, and 48 (47.1%) were co-sleeping. However, 94 (92.2%) of these deaths had at least one risk factor present. Only 8 (7.8%) infants had slept alone, in a crib or bassinet, and on their back or side. Infants less than 4-months-old had a higher rate of co-sleeping (54.7%) than the older infants (25.9%), and a higher frequency of heart malformations at post-mortem examination. The older infants were more likely to exhibit pulmonary and tracheal inflammation, and neuropathology.     

Driving under the influence of alcohol and/or drugs in the Netherlands 1995-1998 in view of the German and Belgian legislation

This study presents the test results of blood and urine samples of impaired drivers in the Netherlands between January 1995 and December 1998. In this period, the blood alcohol concentrations of 11,458 samples have been determined and 1665 blood or urine samples have been analysed for drugs. The median alcohol concentration was between 1.7 and 1.8 mg/ml blood. In 80% of the 1665 analysed samples drugs were detected. At least 42% (702/1665) of the impaired drivers were poly-drug users, with cocaine present in the most frequent combinations. In the Netherlands, the procedure to prove driving under the influence is complex. This procedure can be made more efficient and more effective by embedding the analytical test results, needed to prosecute an impaired driver, in the law. In Belgium and Germany, such laws already are in force. If we would apply the qualifications of the new Belgian law on our analytical data, 67% of the impaired drivers included in this comparison could have been prosecuted without discussion in court.