Bone weathering patterns of metatarsal v. femur and the postmortem interval in Southern Ontario

Twenty-five defleshed pig femora and 25 metatarsals were placed outdoors and observed over 291 days to establish: (1) bone weathering patterns for use in estimating time since death in Southern Ontario and (2) whether larger (femora) or smaller (metatarsals) bones provide a better indicator of time since death. Pig hind limbs were observed to determine a timeline for decomposition of soft tissues during the fall and winter. Ambient air temperature, humidity, precipitation, sunlight, soil pH, and freezing and thawing were considered as factors affecting the breakdown of bone. Weathering patterns were observed based on the extent of bleaching, amount of periosteum and soft tissues present, as well as the appearance of greasiness, cracking and flaking of cortical bone. Both entomological activity and climatic conditions affected soft tissue decomposition. Animal activity affected both the process of bone weathering and soft tissue decomposition, causing variability in sample decomposition and bone breakdown. The variation in microenvironment, partially caused by soil composition, introduced variability in bone weathering rates. Four bone weathering stages were established based on patterns observed. Femora proved to be more resilient and showed more degrees of change due to weathering, thus proving to be a better indicator of time since death than metatarsals.     

Community standards of criminal liability and the insanity defense

Two experiments (N=71) compare lay standards of insanity to standards incorporated in American legal codes. In Experiment 1, case vignettes provided only legally relevant information about defendants' degrees of impairment in cognition or in behavioral control. Respondents' judgments of criminal liability ornot guilty by reason of insanity (NGRI) reflected an exculpatory standard of substantial impairment in both cognition and control. In Experiment 2, case vignettes provided realistic information about defendants' psychiatric diagnoses; respondents had to infer levels of cognitive and control impairment. Results showed that respondents made highly idiosyncratic inferences based on diagnostic categories, but once made, these inferences predicted NGRI judgments. Implications of the concordance between laypeople's rules for assigning NGRI verdicts and the rules used in American legal codes are discussed.Daniel Bailis gratefully acknowledges the support of Public Health Service grant No. 5T32 MH18021-07 for Research Training in Social Psychology during the time in which the present research was conducted. John Darley wished to acknowledge the generous support of the John Simon Guggenheim Foundation and Princeton University. Study 2 presents work done for the Princeton University undergraduate thesis of Tracy Waxman. The authors are grateful to Norman J. Finkel, Valerie Hans, and three anonymous reviewers for comments on an earlier draft on this article.Northwestern University.     

Race/Ethnic-Specific Homicide Rates in New York City: Evaluating the Impact of Broken Windows Policing and Crack Cocaine Markets

The current study evaluated a range of social influences including misdemeanor arrests, drug arrests, cocaine consumption, alcohol consumption, firearm availability, and incarceration that may be associated with changes in gun-related homicides by racial/ethnic group in New York City (NYC) from 1990 to 1999. Using police precincts as the unit of analysis, we used cross-sectional, time series data to examine changes in Black, White, and Hispanic homicides, separately. Bayesian hierarchical models with a spatial error term indicated that an increase in cocaine consumption was associated with an increase in Black homicides. An increase in firearm availability was associated with an increase in Hispanic homicides. Last, there were no significant predictors for White homicides. Support was found for the crack cocaine hypotheses but not for the broken windows hypothesis. Examining racially/ethnically disaggregated data can shed light on group-sensitive mechanisms that may explain changes in homicide over time.     

Determining the sex of human remains through cranial morphology

Sex determination is the keystone of a biological profile, yet few qualitative methods of cranial sex determination have been tested. This analysis examines the accuracy and precision of 17 morphological features of the skull commonly used to determine the sex of unknown skeletal remains. The sample consists of 46 identified skulls from the 19th century St. Thomas' Anglican Church Cemetery in Belleville, Canada. Nasal aperature, zygomatic extension, malar size/rugosity, and supraorbital ridge proved the most useful; of secondary value are chin form and nuchal crest; mastoid size is of tertiary consideration; nasal size and mandibular symphysis/ramus size rank fourth; forehead shape ranks fifth; and palate size/shape are sixth. Skull size/architecture provides an internal standard to assess the relative sizes of other traits. This research is a necessary step in establishing the credibility of morphological sex determination with respect to the Daubert and Mohan criteria for admissibility in a court of law.     

Recognition of cemetery remains in a forensic context

The purpose of this paper is to provide guidelines for the recognition of human remains from modem and historic cemeteries found in a forensic context. Three avenues of evidence may be pursued to confirm the origin of cemetery remains: context, condition of the body, and associated artifacts. This article outlines types of North American cemeteries, demonstrating how land use over time has resulted in many being closed, moved, or forgotten, leaving only the context to indicate their presence. The condition of human cemetery remains varies considerably depending on cultural practices and burial environment, but many exhibit combinations of the following traits: dried or embalmed tissue; erosion of bony pressure points; cortical bone flaking; and bone damage due to autopsy or embalming. Examples of artifact types useful in recognizing cemetery remains are also provided. Two cases from British Columbia, Canada are presented to demonstrate the diagnostic features of a disturbed cemetery burial.     

Crime scene ethics: souvenirs, teaching material, and artifacts

Police and forensic specialists are ethically obliged to preserve the integrity of their investigations and their agencies' reputations. The American Academy of Forensic Sciences and the Canadian Society of Forensic Science provide no guidelines for crime scene ethics, or the retention of items from former crime scenes. Guidelines are necessary to define acceptable behavior relating to removing, keeping, or selling artifacts, souvenirs, or teaching specimens from former crime scenes, where such activities are not illegal, to prevent potential conflicts of interest and the appearance of impropriety. Proposed guidelines permit the retention of objects with educational value, provided they are not of significance to the case, they are not removed until the scene is released, permission has been obtained from the property owner and police investigator, and the item has no significant monetary value. Permission is necessary even if objects appear discarded, or are not typically regarded as property, e.g., animal bones.