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.     

Adverse Childhood Experiences and Criminal Extremity: New Evidence for Sexual Homicide

Adverse childhood experiences are associated with a wide range of behavioral, health, and psychiatric deficits and have recently been used to study the development of serious offending careers. Unfortunately, this research paradigm has largely ignored forensic populations. This study utilized the adverse childhood experiences framework to examine the associations between exposure to violence, victimization, and total adverse childhood experiences on sexual homicide using a sample of 616 incarcerated adult male sexual offenders from Canada 85 of whom committed sexual homicide. Epidemiological tables of odds revealed that a gradient of adverse childhood experiences was associated with sexual homicide, but that the most significant risks were for offenders who had the most extensive abuse histories. In adjusted models, exposure to violence, victimization, and total adverse childhood experiences increased the odds of sexual homicide by 334%, 249%, and 546%, respectively. These effects intensified in models adjusted for childhood enuresis, cruelty to animals, parental abandonment, deviant sexual behaviors, poor self‐image, and sexual problems to 559%, 326%, and 849%, respectively. The adverse childhood experiences framework is a systematic way to organize the criminogenic developmental sequela in sexual homicide.     

Homicide Trends and Illicit Drug Markets: Exploring Differences Across Time

Ample speculation and some evidence suggests that the decline in homicide rates since the early 1990s was partially attributable to declining levels of drug market activity. This analysis explores that explanation, along with an alternative: the strength of the drug market–lethal violence relationship has weakened over time. We outline several conceptual reasons to expect period‐specific differences in the drug market–homicide relationship. These include the aging of market participants, shifts in the normative and transactional climate of markets, and changes in structural factors affecting the magnitude of the relationship between drug market indicators and homicide rates (such as socioeconomic disadvantage). These arguments are evaluated for a sample of large US cities. The results generally show a pattern of attenuation in the drug market–homicide relationship and lead us to conclude that part of the homicide decline is likely due to a drop in the amount of drug market activity, some of it is attributable to the aging of drug market participants, and some appears to be due to unmeasured factors which may have created a “kinder and gentler” drug market.     

Complex Suicide by Self‐stabbing and Drowning: A Case Report and a Review of Literature

Sharp force injuries and drowning are methods exceptionally combined in complex suicides. We report a challenging case of complex suicide by self‐stabbing and drowning that illustrates the difficulty in discriminating between homicide and suicide in such circumstances of death. The corpse of a young man was found submerged in a river, stabbed nine times with two wounds that had penetrated the thorax and had caused lung injuries and a hemopneumothorax. The postmortem and histological examinations were consistent with a death caused by drowning, but the manner of death still remained undetermined. Police investigation finally concluded to a suicide, although no suicide note had been left and the victim had no underlying diagnosed mental disorder. The parameters that may help distinguish suicide from homicide at the autopsy should be interpreted in light of a thorough forensic investigation to determine the exact manner of death in such a case.     

Neuropsychological and Criminological Features of Female Homicide Offenders

Few studies have examined life history and cognitive characteristics unique to female homicide offenders. Understanding these characteristics could aid in risk assessment for extreme violence in this group of offenders. The current study utilized t‐tests or chi‐square tests to compare 27 female and 81 male homicide offenders on psychiatric, neurologic, criminal, and cognitive characteristics. Additionally, we explored the role of abuse history in female offenders through Kruskal–Wallis or Fisher's exact tests. Results indicate that in comparison with male counterparts, females are more likely to have history of mood disorder, borderline personality disorder, and abuse. Cognitively, female homicide offenders exhibit circumscribed cognitive impairment in verbal abilities and perform similarly to male homicide offenders across most cognitive tasks. Within the female offender group, history of sexual abuse is associated with higher rates of impulsive homicide and poorer verbal abilities. These findings provide preliminary evidence for distinct factors associated with homicide in women.     

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.     

EXAMINING THE CONDITIONAL NATURE OF THE ILLICIT DRUG MARKET-HOMICIDE RELATIONSHIP: A PARTIAL TEST OF THE THEORY OF CONTINGENT CAUSATION

Recently, Zimring and Hawkins (1997) have suggested that drug markets are a “contingent cause” of the increase in homicide rates. That is, where structural conditions known to produce violence are already in place, the drug distribution‐homicide link may be exacerbated. This analysis uses hierarchical linear modeling to investigate two key research questions: (1) Is within‐city variation in illicit drug market activity positively associated with within‐city variation in homicide rates during the 1984–1997 period? (2) Is the illicit drug market‐homicide association contingent on preexisting violence conducive socioeconomic conditions? Using three measures of drug market activity, analyses provide affirmative evidence on both questions. Theoretical and research implications of these findings are discussed.     

COMMUNITIES,STREET GUNS AND HOMICIDE TRAJECTORIES IN CHICAGO, 1980–1995: MERGING METHODS FOR EXAMINING HOMICIDE TRENDS ACROSS SPACE AND TIME*

We merge Exploratory Spatial Data Analysis (ESDA) and a semi‐parametric, group‐based trajectory procedure (TRAJ) to classify communities in Chicago by violence trajectories across space. Total, street gun and other weapon homicide trajectories are identified across 831 census tracts between 1980 and 1995. We find evidence consistent with a weapon substitution effect in violent neighborhoods that are proximate to one another, a defensive diffusion effect of exclusively street gun‐specific homicide increases in neighborhoods bordering the most violent areas, and a spatial decay effect of temporal homicide trends in which the most violent areas are buffered from the least violent by places experiencing mid‐range levels of lethal violence over time. In merging these two methods of data analysis, we provide a more efficient way to describe both spatial and temporal trends and make significant advances in furthering applications of space‐time methodologies.     

Controversial Suicide Case Using a Submachine Gun with a Sound Suppressor—The Need of Team Work of Forensic Chemistry and Firearm Examiners

Evidence materials in a presumed suicide case were studied by a firearm examiner and a forensic chemist. The victim's body with double gunshot wounding in his forehead, a machine gun in the sustained fire mode with a silencer, and four cartridge cases were found. Examinations of the evidence, the case file studies, and experiments dedicated to the case were carried out. Relationships between the placement of cartridge cases and the gun were established using a fast camera. The distributions of gunshot residues on the evidence materials and within the comparative gunshot patterns were studied by means of optical and electron microscopy, X‐ray microanalysis, and infrared spectroscopy. The shooting distance was assessed to be 30 cm or more, whereas the greatest distance that could have been achieved by the victim himself was about 11–13 cm. The obtained results supported the version of homicide rather than suicide.     

A Qualitative Assessment of Stress Perceptions Among Members of a Homicide Unit

Existing research on stress among police assumes the presence of uniform stressors across job roles and borrows upon generic stress instruments to tap stress types and levels. The present study draws upon interviews with 26 members of a metropolitan homicide unit to provide an inductive vantage point on stress perceptions within a specialized area of policing. We provide evidence that the occupational and organizational forms of stress detailed by these officers are shaped largely by the unique nature of homicide work. Among the unique task-related stressors observed include the complexities of homicide crime scenes, time pressures, cases assignment factors, paperwork demands, and long-term ownership over individual case files. A series of structural issues from both within and outside the police agency are identified as organizational stressors unique to homicide work. We conclude with a proposed theory of homicide investigator stress and implications for future research.     

Weapon Use in Korean Homicide: Differences Between Homicides Involving Sharp and Blunt Instruments

On the basis of information regarding 276 homicides committed in South Korea between 1987 and 2008, we compared offenders’ and victims’ characteristics, injury locations, weapon‐related behavior, and offending behavior between homicides involving sharp and blunt instruments. The victims of sharp‐force homicide were much younger relative to those of blunt‐force homicide. In addition, homicides involving blunt instruments were more likely to be committed by offenders who lived with the victims. Most sharp‐force homicides involved injuries to the torso, while blunt‐force homicides involved mainly head injuries. Furthermore, perpetrators of sharp‐force homicides tended to preselect their weapons, while those of blunt‐force homicides were likely to use weapons of opportunity. Logistic regression analysis identified a number of factors, including injury location and body transportation, which significantly predicted weapon type. As this was the first South Korean study to compare sharp‐ and blunt‐force homicides, the results have practical implications for homicide investigations.     

Determined to Die! Ability to Act Following Multiple Self‐inflicted Gunshot Wounds to the Head. The Cook County Office of Medical Examiner Experience (2005–2012) and Review of Literature

Cases of multiple (considered 2+) self‐inflicted gunshot wounds are a rarity and require careful examination of the scene of occurrence; thorough consideration of the decedent's psychiatric, medical, and social histories; and accurate postmortem documentation of the gunshot wounds. We present a series of four cases of multiple self‐inflicted gunshot wounds to the head from the Cook County Medical Examiner's Office between 2005 and 2012 including the first case report of suicide involving eight gunshot wounds to the head. In addition, a review of the literature concerning multiple self‐inflicted gunshot wounds to the head is performed. The majority of reported cases document two gunshot entrance wound defects. Temporal regions are the most common affected regions (especially the right and left temples). Determining the capability to act following a gunshot wound to the head is necessary in crime scene reconstruction and in differentiation between homicide and suicide.     

Putting homicide followed by suicide in context: Do macro‐environmental characteristics impact the odds of committing suicide after homicide?*

Homicide followed by suicide remains an understudied phenomenon in the criminological literature. This is due, in part, to methodological and statistical limitations—much of the extant research includes small samples and has not kept pace with quantitative advances. Moreover, scholarship on homicide–suicide has been focused almost exclusively on individual risk factors, discounting contextual influences. In this study, we examine whether macro‐environmental characteristics affect the odds of suicide after a homicide. We use data on 24,373 homicide and homicide–suicide cases distributed across 3,019 cities and 48 U.S. states from the National Violent Death Reporting System to examine the direct effects of structural factors on the odds of suicide after a homicide; and whether structural characteristics condition the impact of the victim–offender relationship on the odds of homicide–suicide. Hierarchical logistic regression models indicate that macro‐level concentrated disadvantage decreases the odds of homicide–suicide. Furthermore, concentrated disadvantage attenuates the odds of suicide after the homicide of an intimate partner, child, family member, or friend, relative to the killing of a stranger. The findings reveal that researchers should account for the context in which homicide–suicide occurs; failure to do so may unintentionally discount a key correlate of homicide–suicide and artificially inflate the effects of the micro‐environment.     

Unusual circumstances in a fourfold complex suicide

Complex suicides are defined as suicides using more than one method, which may sometimes suggest homicide. We present the case of a 27-year-old man who killed himself by using four different methods. The man was known as a loner and sufferd from bipolar psychosis. An eyewitness saw him afire and falling out of a window on the 4th floor of a hotel. He was wearing a judo dress with the belt wound twice around his neck. He died in a hospital about two hours later. The autopsy showed signs of neck compression typical of (self)-strangulation, several stab and cut wounds in the thoracic and abdominal region from sharp force, extensive first- to third-degree burns caused by the effect of heat, contusions of internal organs, serial rib fractures and several bone fractures of the extremities as signs of blunt force. The CO-Hb value in the blood amounted to 7%; the other toxicological tests were negative. Death was found to be due to exsanguination from a deep stab wound in the abdomen and multiple trauma caused by the fall from a great height in the course of a suicide. Homicide could be excluded due to the circumstances of the case, which demonstrated again that both the medical findings and the investigation results of the police are indispensable for the differentiation between suicide and homicide.     

Introducing 3D Printed Models as Demonstrative Evidence at Criminal Trials

This case report presents one of the first reported uses of a 3D printed exhibit in an English homicide trial, in which two defendants were accused of beating their victim to death. The investigation of this crime included a micro‐CT scan of the victim's skull, which assisted the pathologist to determine the circumstances of the assault, in particular regarding the number of assault weapons and perpetrators. The scan showed two distinct injury shapes, suggesting the use of either two weapons or a single weapon with geometrically distinct surfaces. It subsequently served as the basis for a 3D print, which was shown in court in one of the first examples that 3D printed physical models have been introduced as evidence in a criminal trial in the United Kingdom. This paper presents the decision‐making process of whether to use 3D printed evidence or not.     

Forensic Evidence in Homicide Investigations and Prosecutions

Even though forensic evidence is collected at virtually every homicide scene, only a few studies have examined its role in investigation and prosecution. This article adds to the literature by providing the results of a study of 294 homicide cases (315 victims) occurring in Cleveland, Ohio, between 2008 and 2011. Through a logistic regression on open versus closed cases, the collection of knives, administration of gunshot residue (GSR) kits, and clothing at the scene were positively and significantly related to case closures, while collection of ballistics evidence and DNA evidence were statistically significant in the opposite direction. With regard to analysis, the clearance rate for cases with probative results (i.e., matches or exclusions) was 63.1% compared to a closure rate of 56.3% for cases without probative results. However, only 23 cases had probative results prior to arrest compared to 128 cases with probative results after arrest.     

Different Mechanisms of Decapitation: Three Classic and One Unique Case History

Abstract: Three classic cases and one exceptional case are reported. The unique case of decapitation took place in a traffic accident, while the others were seen after homicide, vehicle‐assisted suicide, and after long‐jump hanging. Thorough scene examinations were performed, and photographs from the scene were available in all cases. Through the autopsy of each case, the mechanism for the decapitation in each case was revealed. The severance lines were through the neck and the cervical vertebral column, except for in the motor vehicle accident case, where the base of skull was fractured. This case was also unusual as the mechanism was blunt force. In the homicide case, the mechanism was the use of a knife combined with a saw, while in the two last cases, a ligature made the cut through the neck. The different mechanisms in these decapitations are suggested.     

Elasticity in evaluations of criminal evidence: Exploring the role of cognitive dissonance

Purpose. Previous experiments have demonstrated asymmetrical scepticism in investigators' judgments of criminal evidence – evidence inconsistent (vs. consistent) with the dominant hypothesis about a case is judged as less reliable. In addition, some types of evidence (e.g., witness testimony) are more susceptible to asymmetrical scepticism than others (e.g., DNA evidence), indicating varying degrees of elasticity. This article proposes that inconsistent evidence arouses cognitive dissonance, and that the dissonance can be reduced through either asymmetrical scepticism (for high‐elasticity evidence) or belief change (for low‐elasticity evidence). The hypotheses are tested in two experiments. Methods. In both experiments, law students made a preliminary judgment about the guilt of a suspect in a homicide case, and subsequently received a piece of DNA or witness evidence which was either consistent or inconsistent with the preliminary judgment. The extent to which participants changed their guilt judgments, judged the additional evidence as reliable, and felt dissonance served as the main dependent variables. Results. Inconsistent (vs. consistent) evidence did arouse stronger dissonance, but only for witness (and not DNA) evidence. Experienced dissonance (Experiment 1) and dissonance reduction (Experiment 2) accounted for the effect of the evidence on changes in guilt judgments, but not for the effect on reliability judgments. The greatest dissonance reduction was observed among participants who received inconsistent witness evidence but did not change their guilt judgments accordingly. Conclusions. It appears that dissonance plays a significant, although complex, role in investigative judgments of guilt and reliability. Alternative dissonance‐reducing mechanisms that can account for the findings and practical implications are discussed.