Joan A. Bytheway

A geometric morphometric approach to sex determination of the human adult os coxa.

Abstract:  Sex determination of the human skeleton is best assessed from the os coxa. The present study explored the possibility of using three‐dimensional landmark coordinate data collected from various landmarks located over the entire bone to determine whether there were significant sex differences local to the landmarks. Thirty‐six landmarks were digitized on 200 African American and European American male and female adult human os coxae. MANCOVA results show that sex and size have a significant effect on shape for both European Americans (Sex, F = 17.50, d.f. = 36, 63, p > F = 0.0001; Size, F = 2.56, d.f. = 36, 63, p > F = 0.0022) and African Americans (Sex, F = 21.18, d.f. = 36, 63, p > F = 0.0001; Size, F = 2.59, d.f. = 36, 63, p > F = 0.0005). The discriminant analysis shows that sexing accuracy for European Americans is 98% for both males and females, 98% for African American females, and 100% for African American males.

Exclusion of forensically important flies due to burying behavior by the red imported fire ant (Solenopsis invicta) in southeast Texas

On March 3, 2009, the remains of an adult male were partially buried at the Southeast Texas Applied Forensic Science (STAFS) Facility at the Center for Biological Field Studies (CBFS), Sam Houston State University, Texas. The individual was buried except for a small portion of the left abdominal region. A postmortem incised wound was created in the exposed area with the intention of attracting carrion flies. Worker ants of a colony of Solenopsis invicta Buren 1972 (red imported fire ant) filled in the wound with soil, thereby monopolizing the exposed area of the corpse and excluding expected carrion insects from the wound. During the bloating phase, approximately nine days after burial, normal decomposition processes of the gut created a sufficient disruption of the ants, such that flies oviposited and larvae were able to colonize the corpse. Estimation of the postmortem interval (PMI) based on the minimum period of fly activity would be severely skewed should the remains be discovered at this point and growth rate of Diptera larvae be used as the primary determinant for the PMI. While S. invicta is an expected member of a carrion ecosystem in southeastern Texas, and is known to distort the PMI estimation through larval and egg removal, the complete exclusion of flies from the wound by the burial behavior of S. invicta was an unexpected and until now an unpublished occurrence.

Interobserver Reliability of the Total Body Score System for Quantifying Human Decomposition

Several authors have tested the accuracy of the Total Body Score (TBS) method for quantifying decomposition, but none have examined the reliability of the method as a scoring system by testing interobserver error rates. Sixteen participants used the TBS system to score 59 observation packets including photographs and written descriptions of 13 human cadavers in different stages of decomposition (postmortem interval: 2–186 days). Data analysis used a two‐way random model intraclass correlation in SPSS (v. 17.0). The TBS method showed “almost perfect” agreement between observers, with average absolute correlation coefficients of 0.990 and average consistency correlation coefficients of 0.991. While the TBS method may have sources of error, scoring reliability is not one of them. Individual component scores were examined, and the influences of education and experience levels were investigated. Overall, the trunk component scores were the least concordant. Suggestions are made to improve the reliability of the TBS method.

Application of soil in forensic science: residual odor and HRD dogs.

Decomposing human remains alter the environment through deposition of various compounds comprised of a variety of chemical constituents. Human remains detection (HRD) dogs are trained to indicate the odor of human remains. Residual odor from previously decomposing human remains may remain in the soil and on surfaces long after the remains are gone. This study examined the ability of eight nationally certified HRD dogs (four dual purpose and four single purpose) to detect human remains odor in soil from under decomposing human remains as well as soils which no longer contained human remains, soils which had been cold water extracted and even the extraction fluid itself. The HRD dogs were able to detect the odor of human remains successfully above the level of chance for each soil ranging between 75% and 100% accurate up to 667 days post body removal from soil surface. No significant performance accuracy was found between the dual and single purpose dogs. This finding indicates that even though there may not be anything visually observable to the human eye, residual odor of human remains in soil can be very recalcitrant and therefore detectible by properly trained and credentialed HRD dogs. Further research is warranted to determine the parameters of the HRD dogs capabilities and in determining exactly what they are smelling.

Comparing the Scoring of Human Decomposition from Digital Images to Scoring Using On-site Observations

When in forensic casework or empirical research in‐person assessment of human decomposition is not possible, the sensible substitution is color photographic images. To date, no research has confirmed the utility of color photographic images as a proxy for in situ observation of the level of decomposition. Sixteen observers scored photographs of 13 human cadavers in varying decomposition stages (PMI 2–186 days) using the Total Body Score system (total n = 929 observations). The on‐site TBS was compared with recorded observations from digital color images using a paired samples t‐test. The average difference between on‐site and photographic observations was −0.20 (t = −1.679, df = 928, p = 0.094). Individually, only two observers, both students with <1 year of experience, demonstrated TBS statistically significantly different than the on‐site value, suggesting that with experience, observations of human decomposition based on digital images can be substituted for assessments based on observation of the corpse in situ, when necessary.

Recognition of Atypical Burn Patterns and Pre-cremation Blunt Force Trauma Observed on Human Remains in Two Forensic Cases in the United States

The normal burn pattern of bone color in humans described and illustrated by Symes and colleagues from unintentional fires was compared to the burn patterns seen in two forensic cases from Texas and North Carolina that involved the intentional burning of two victims. Heat altered bone exhibits a range of colors (e.g. white, blue-grey, black, and yellow) from the highest to the lowest exposure of heat. In the Texas case, atypical burn patterns were evinced by an asymmetrical burn pattern on the skull and lower body as well as by the predominantly calcined upper body with a charred lower body. The thermal pattern seen on the body of the North Carolina victim was consistent with a longer heat exposure to the trunk and left side of the body. In both cases, thermal damage did not obscure per mortem blunt force trauma. The atypical burn patterns were diagnostic of intentional fires and contributed to the reconstruction of the events of the crime.

Necrophagous caterpillars provide human mtDNA evidence.

Abstract:  Decomposition of large mammalian carcasses is greatly accelerated through the action of insects. Specialized feeders capable of digesting keratin and collagen found in skin, hair, and tendons and ligaments are attracted to corpses in late stages of dry decomposition and include Tinea pellionella, the casemaking clothes moth, and Tineola bisselliella, the webbing clothes moth (Lepidoptera; Tineidae). Until now, details of the caterpillar behavior as necrophagous insects were vague. Here, we detail the behavior of each species and document the incorporation of human hair into the portable larval shelters constructed by the caterpillars of T. pellionella. Hair of the decedent used as building material for caterpillar shelters provided enough starting template to amplify and sequence the HVI and HVII sections of the control region (mtDNA) of the decedent.

The Ethics and Best Practices of Human Decomposition Facilities in the United States

ABSTRACT Taphonomists working with the recently dead find a lack of standards and best practices to guide them in the ethical treatment of human remains. The research is not covered by Institutional Review Boards (IRBs), where the federal guidelines specifically include “live human subjects.” Neither are the human dead covered in the guidelines issued by the U.S. Department of Agriculture for animal research. Most universities have no guidelines for research using the recently dead. Medical research has proposed some guidelines (1), however, taphonomic research differs in the longevity of the research and the disposition of the remains. The standards and ethics in working with the recently dead can be guided by the same fundamental principles outlined in the Belmont Report (2)–respect for persons, beneficence, and justice. This paper outlines some of the issues relevant to current decomposition research facilities and suggests guidelines and best practices.

A Hydrologic Retention System and Water Quality Monitoring Program for a Human Decomposition Research Facility: Concept and Design*

Forensic taphonomy is an essential research field; however, the decomposition of human cadavers at forensic science facilities may lead to nutrient loading and the introduction of unique biological compounds to adjacent areas. The infrastructure of a water retention system may provide a mechanism for the biogeochemical processing and retention of nutrients and compounds, ensuring the control of runoff from forensic facilities. This work provides a proof of concept for a hydrologic retention system and an autonomous water quality monitoring program designed to mitigate runoff from The Southeast Texas Applied Forensic Science (STAFS) Facility. Water samples collected along a sample transect were analyzed for total phosphorous, total nitrogen, NO3− , NO2− , NH4, F−, and Cl−. Preliminary water quality analyses confirm the overall effectiveness of the water retention system. These results are discussed with relation to how this infrastructure can be expanded upon to monitor additional, more novel, byproducts of forensic science research facilities.