A new type of shotgun ammunition produces unique wound characteristics

The Tucson Police Department, Tucson, AZ, has begun using the Polyshok Impact Reactive Projectile (IRP), a new type of shotgun ammunition that includes a lead bead core that travels within single, plastic-encased projectile. On impact, the core is released to distribute over a small area, thereby disintegrating on impact to reduce the likelihood of exit or collateral damage on missed shots. After a brief review of shotgun slug ballistics and wound characteristics and a discussion of the mechanism of the Polyshok IRP, we report the first death in the United States from this ammunition. Findings included a single entrance wound with plastic ammunition components and small lead particles recovered from the body, the combination of which normally would suggest a close-range shooting with birdshot. However, the characteristics of this ammunition create different patterns than are found with slugs or shot, so that a medical examiner unfamiliar with the Polyshok IRP could draw inaccurate conclusions about ammunition and range of fire. Because the single projectile fired from this ammunition is composed of both plastic and lead, plastic components are likely to be found within the wound at any range of fire, unlike traditional shot or slug ammunition. Also, the small size of lead particles found spread through the wound cavity would ordinarily suggest a small-size shot, whereas the external appearance of the wound (a single entrance with no dispersion of shot) and the pattern of tissue destruction are more consistent with the patterns of injury associated with shotgun slugs.     

A distant-range, suicidal shotgun wound of the back

The case being reported is one of a shotgun fatality with a thoracic back wound. A 23-year-old man was shot from a distance with trajectories going from back to front and on a nearly horizontal level. These findings observed in the autopsy could represent homicide, but scene investigation and police records were interpreted and it became clear that the case was suicide. Thus, this case shows that the determination of the manner of death requires a careful forensic investigation including autopsy findings, scene investigation, and reconstruction of the events.     

Firing distance estimates with pellet dispersion from shotgun with various chokes: an experimental, comparative study

There are several studies suggesting models for firing distance estimation due to pellet dispersion, but few of them consider the degree of choke of a shotgun. The purpose of this research is to suggest some models for estimation of the firing distance for choked and cylinder bore shotguns. Twelve gauge with full chokes, and 12 and 16 gauge with cylinder bore shotguns were fired with #2 and #5 shots from 75, 100, 300, 500, and 1000 cm distances. Statistically significant pellet dispersion values were found for each shotgun by using #2 and #5 shots for different firing distances. All the data obtained were analyzed with linear regression and four models were constituted. Investigators should use special formulae for each shotgun, degree of choke, and pellet type while determining the firing distance. Therefore, more experimental and comparative studies should be designed for each type.     

A case of stalking in the workplace and subsequent sexual homicide

A case of stalking in the workplace and subsequent sexual homicide by a 33-year-old male is reported. Following several months of stalking a 38-year-old female, the male subject went to the woman's office after business hours and restrained, raped, and murdered her. The cause of death was multiple stab wounds. The facts of the case reveal that the subject fits a predatory-type stalker, which represents a small subgroup within stalkers that has received little attention. Unlike other types of stalkers, the predatory stalker gives little warning to their victim (or multiple victims), as their stalking behaviors tend not to be very invasive or harassing. In general, most stalkers are not physically violent; however, predatory-type stalkers, given their tendency for sexual violence, are dangerous and the importance of identifying them is emphasized. Factors associated with perpetrators of sexual homicide are discussed.     

Extent, trends, and perpetrators of prostitution-related homicide in the United States

Prostitute women have the highest homicide victimization rate of any set of women ever studied. We analyzed nine diverse homicide data sets to examine the extent, trends, and perpetrators of prostitution-related homicide in the United States. Most data sources substantially under-ascertained prostitute homicides. As estimated from a conservative capture-recapture analysis, 2.7% of female homicide victims in the United States between 1982 and 2000 were prostitutes. Frequencies of recorded prostitute and client homicides increased substantially in the late 1980s and early 1990s; nearly all of the few observed pimp homicides occurred before the late 1980s. These trends may be linked to the rise of crack cocaine use. Prostitutes were killed primarily by clients, clients were killed mainly by prostitutes, and pimps were killed predominantly by pimps. Another conservative estimate suggests that serial killers accounted for 35% of prostitute homicides. Proactive surveillance of, and evidence collection from, clients and prostitutes might enhance the investigation of prostitution-related homicide.     

A case of suicidal suffocation simulating homicide

This case concerns an unusual suicidal plastic bag suffocation. An elderly white man was found dead and partially disrobed in his apartment lying supine on a sofa with a plastic bag closed by a rope over the head and the upper and lower extremities tightly tied with two other ropes, the end of both arranged into slipknots (self-rescue mechanism). Police investigations found no pornography in the apartment, and circumstantial data alleged no psychiatric disorders or suicidal intentions. The autopsy excluded signs of struggle and sexual intercourse as well as any type of injury or physical illness. Chemical analyses on the peripheral blood excluded acute drugs and/or alcohol intoxication. A differential diagnosis of the manner of death was performed, including scenarios of accidental autoerotic asphyxiation, homicide during either sexual activity or ritualistic, elderly suicide. The collected data most strongly supported the hypothesis of a suicidal asphyxiation simulating homicide to devolve a life insurance to the victim's sons because of economic difficulties.     

Aqua-eroticum: an unusual autoerotic fatality in a lake involving a home-made diving apparatus

The term Aqua-eroticum was first introduced in 1984 by Sivaloganathan to describe the unusual autoerotic death of a man using submersion as an asphyxia method. This was the first case of that kind, and since then, no other case of autoerotic submersion has been reported, nor other autoerotic fatality in open water. Here we report the case of a 25-year-old man, nude under a home-made plastic body suit, overdressed for the season with winter clothes and restrained by complex bondage. He was submersed, tied underwater to a boat and was using a home-made diving apparatus for air supply. Death was ruled as accidental autoerotic asphyxia from rebreathing, caused by the faulty air-supply device.     

Collembola of the grave: a cold case history involving arthropods 28 years after death

This report describes a cold case in which a cadaver of a 28-year-old female was exhumed in February 2005 from a cemetery in Battle Creek, Michigan. She had sustained a gunshot wound to the head and was found dead in her home on November 15, 1977. The body of the victim was subsequently embalmed and then buried at a depth of 1.8 m in an unsealed casket that was placed inside an unsealed cement vault. The exhumation yielded thousands of live specimens of a single species of the order Collembola or spring tails, Sinella (Coecobrya) tenebricosa (Entomobryidae). This species is considered to be a "tramp" species, cosmopolitan in the United States and Canada. Due to the ideal environmental conditions at the site, the population of this species underwent growth and development inside the casket for a number of years. Collected with the Collembola were large numbers of Acarina (mites) of the Family Glycyphagidae, and fly puparia, Conicera tibialis Schmitz (Order: Diptera, Family: Phoridae), also known as coffin flies. These invertebrates are sometimes mentioned by forensic investigators as occurring on corpses in graves, but aspects of their life history are rarely described. The species of Collembola that was found surviving and reproducing on this corpse in a casket exhumed after 28 years was the oldest reported grave site occurrence for any collembolan species based on a survey of the literature back to 1898.     

Caddisflies assist with homicide case: determining a postmortem submersion interval using aquatic insects

Although few indicators of time since death for corpses found in aquatic ecosystems are comparable in precision to the insect indicators used in terrestrial cases, there are observations that can be useful in suggesting or ruling out an approximate PMSI (postmortem submersion interval). For example, the time intervals required for certain growth phases of aquatic insects, such as caddisflies, that may attach themselves to the submerged remains can be used to estimate a minimum PMSI. Approximately 8 of the 13 orders of insects containing species with aquatic or semi-aquatic stages are likely to be associated with carrion or corpses in aquatic habitats. We present a case study in which portions of a body from an adult male were discovered in a south central Michigan stream. The body was dismembered and portions were recovered from two bags floating and submerged in the stream. Insect specimens collected from mesh and plastic bags consisted of one fly larva belonging to the family Muscidae, and caddisfly larvae belonging to two families: the Limnephilidae. (case-makers) and the Hydropsychidae, (net spinners). We used unique case-building behaviors of the limnephilid caddisflies found on the remains to elucidate a PMSI range consistent with the disappearance of the victim. It is important for forensic investigators to understand that although some precision is lost in estimating a PMSI with aquatic insects, these organisms should not be ignored in gathering evidence from aquatic crime scenes, and in fact, they can provide valuable details in estimating a PMSI.     

Distinguishing between homicide and suicide knots and ligatures: A comparative analysis of case and survey data

Distinguishing between suicide and homicide can be challenging owing to ambiguous and confusing case details. In particular, there is a paucity of useful information comparing homicide and suicide knots and ligatures in the literature. Multiple knot and ligature characteristics have not been recognized previously because complete and accurate information has been lacking. Ninety external tying cases (mainly homicide) and 56 cases involving self‐tying (mainly suicide) were reviewed to compare multiple knot and ligature characteristics. Additionally, 189 survey volunteers performed four standardized external tying tasks and two self‐tying tasks, yielding comparison data from more than 1500 knots. Using all available data, it was determined that the differences between external and self‐tying included types of knots, ligature configurations, ligature tensions, wrist gaps, wend lengths, knot access, external anchoring, and other indicators. These differences are presented in a proposed analysis checklist inspired by medical and psychiatric protocols. The checklist contains 14 potential characteristics for head and neck bindings, 14 potential characteristics for wrists and arms, nine ankle and leg characteristics, and four linkage details. The proposed checklist can be expanded and fine‐tuned as more data are accumulated. It offers experienced knot analysts an additional tool to assist in drawing conclusions, which then can be related to other case evidence by investigators.     

A radiographic assessment of pediatric fracture healing and time since injury

Past studies and pediatric bone physiology indicate that younger individuals may heal at a faster rate. Additionally, in adults upper limb fractures heal faster than lower limb fractures; this trend is expected for pediatric fractures. This study aims to evaluate and compare rates of fracture repair in children based on age and skeletal element. Six stages are used to describe the bone repair process in 294 radiographs of tibial and radial fractures from 107 infants and young children. Healing rates are examined using ANOVA and Welch's t-test with a 95% confidence interval. Results indicate that younger individuals spend less time at stage 1, suggesting a delay in the start of healing. Furthermore, forearm fractures heal faster than leg fractures at stages 2 and 3, suggesting a role in the osseous reaction of bone healing. The healing schedule presented may allow the timing of injuries to be estimated from radiographs.     

Assessing Cognitive Bias in Forensic Decisions: A Review and Outlook

In recent years, a number of studies have demonstrated that forensic examiners can be biased by task-irrelevant contextual information. However, concerns relating to methodological flaws and ecological validity attenuate how much the current body of knowledge can be applied to real-life operational settings. The current review takes a narrative approach to synthesizing the literature across forensic science. Further, the review considers three main issues: (i) primary research on contextual bias within forensic science; (ii) methodological criticisms of this research; (iii) an alternative perspective that task-irrelevant contextual information does not always lead to error. One suggestion for future research is outlined, which is that studies on contextual bias in forensic decisions should be conducted in collaboration between forensic scientists and cognitive psychologists. Only then can rigorous and ecological valid experiments be created that will be able to assess how task-irrelevant contextual information influences forensic analysis and judgments in operationally valid settings.     

Indoor Wet Screening of Exhumed Skeletal Remains: A Suggested Procedure for the Preparation of Fragile Evidence for Anthropological Analysis

Abstract: The 2007 exhumation of three children’s graves, located in rural upstate New York and dating to 1979 and 1980, was warranted as their mother had come under suspicion for the death of a child she had been babysitting in late 2006. The local March weather conditions had been wet, and heavy rains fell during the 2‐day process of casket removal. The extremely wet soil and the poor preservation of two wooden caskets increased the likelihood of damage to evidence. After remains’ transport to the forensic center, an indoor wet‐screening station was established so that skeletal elements could be (i) separated from soil matrix and (ii) preserved carefully for analysis. Not only were the remains relatively small and fragile in comparison with those of an adult, but two of the three remains were known to be fire damaged, thus the use of special laboratory preparation techniques was crucial.     

Probability of exclusion in paternity testing: time to reassess

The average exclusion probability is a measure of efficiency in paternity testing; it refers to the a priori ability of a battery of tests to detect paternity inconsistencies. This parameter measures the capacity of the system to detect a false accusation of paternity. Traditionally, this average exclusion probability has been estimated as the probability of excluding a man who is not the father by an inconsistency in at least one of the studied loci. We suggest that this criterion should be corrected, as currently the presumed father is excluded when at least three genetic inconsistencies are found with the child being tested, not just one. This change of criterion has occurred because of the use of microsatellite loci, whose mutation rates are much greater than those of the coding genes used previously in paternity studies. We propose the use of the average probability of exclusion for at least three loci (not only one), as an honest measure of the combined probability of exclusion of several loci, and we propose an algebraic expression to calculate it.     

A View to the Future: A Novel Approach for 3D–3D Superimposition and Quantification of Differences for Identification from Next‐Generation Video Surveillance Systems

Techniques of 2D–3D superimposition are widely used in cases of personal identification from video surveillance systems. However, the progressive improvement of 3D image acquisition technology will enable operators to perform also 3D–3D facial superimposition. This study aims at analyzing the possible applications of 3D–3D superimposition to personal identification, although from a theoretical point of view. Twenty subjects underwent a facial 3D scan by stereophotogrammetry twice at different time periods. Scans were superimposed two by two according to nine landmarks, and root‐mean‐square (RMS) value of point‐to‐point distances was calculated. When the two superimposed models belonged to the same individual, RMS value was 2.10 mm, while it was 4.47 mm in mismatches with a statistically significant difference (p < 0.0001). This experiment shows the potential of 3D–3D superimposition: Further studies are needed to ascertain technical limits which may occur in practice and to improve methods useful in the forensic practice.     

The Applicability of the Lamendin Method to Skeletal Remains Buried for a 16-Year Period: A Cautionary Note

The Lamendin method is widely reported as one of the most reliable means of age estimation of skeletal remains, but very little is known concerning the influence of burial in soil. This study aimed at verifying the reliability of the Lamendin method on corpses buried for 16 years in a cemetery. The Lamendin and the Prince and Ubelaker methods were applied. In all age groups except the 40- to 49-year–olds, the error was higher in the buried sample. The age-at-death error ranged between 10.7 and 36.8 years for the Lamendin method (vs. the reported 7.3–18.9 years) and 9.5 and 35.7 for the Prince and Ubelaker one (vs. the original 5.2–32.6 years); in all age groups, the error is closer to that found on archeological populations. These results suggest caution in applying the Lamendin method to forensic cases of human remains buried even for a brief period under soil.     

A New Index for the MMPI‐2 Test for Detecting Dissimulation in Forensic Evaluations: A Pilot Study

This pilot study is the starting point of a potentially broad research project aimed at identifying new strategies for assessing malingering during forensic evaluations. The forensic group was comprised of 67 males who were seeking some sort of certification (e.g., adoption, child custody, driver's license, issuance of gun permits, etc.); the nonforensic group was comprised of 62 healthy male volunteers. Each participant was administered the MMPI‐2. Statistical analyses were conducted on obtained scores of 48 MMPI‐2 scales. In the first step, parametric statistics were adopted to identify the best combination of MMPI‐2 scales that differentiated the two groups of participants. In the second step, frequency‐based, nonparametric methods were used for diagnostic purposes. Results: A model that utilized the best three predictors (“7‐Pt”, “L,” and “1‐Hs”) was developed and used to calculate the Forensic Evaluation Dissimulation Index (FEDI), which features satisfactory diagnostic accuracy (0.9), sensitivity (0.82), specificity (0.81), and likelihood ratio indices (LR+ = 4.32; LR? = 0.22).