Forensic Research
The forensic science faculty are actively conducting and publishing forensically relevant research (see Publications). In general, forensic science research at UNL falls into two categories: forensic taphonomy and bloodstain pattern analysis. Within these fields we aim to contribute to the estimation of postmortem interval, identification of clandestine graves and gravesoils, and crime scene reconstruction based on bloodstain pattern analysis.
Estimation of Postmortem Interval
An accurate estimation of postmortem interval (PMI) is critical to all death investigations. Arguably, forensic entomology represents the most accurate, efficient and effective means to estimate PMI. However, many questions still need to be answered. Are current degree day models sufficiently accurate in post-Daubert proceedings? How does light and other environmental parameters effect larval development? How can we better identify forensically important insects? At UNL we are actively seeking answers to these, and many other, questions related to forensic entomology.
Estimations of PMI become less accurate as decomposition proceeds. As informative as insects are, even they can lose much of their forensic value once they leave a cadaver to pupate, i.e. PMI estimations are typically limited to season of death. We aim to increase the accuracy of the estimation of extended PMI by investigating the processes that occur in soils associated with cadavers (gravesoils). Previous work at the University of Tennessee-Knoxville has shown that a soil-based method is valid. We are currently investigating the forensic application of gravesoil processes in further detail.
Identification of Clandestine Graves
In some cases, it is known that a body has been disposed of in an outdoor setting. However, the exact location of the body might be unknown. We are currently investigating the chemical and biological effects of surface and buried remains to aid in the location of clandestine death sites. These investigations are based on the observation that a body releases a significant amount of energy and nutrients during decomposition. Some of these nutrients, particularly nitrogen, have a significant effect on the surrounding environment. These effects appear to have great potential for locating graves and death sites that were meant to be hidden.
Bloodstain Pattern Analysis
Scenes of violent crime are often associated with bloodstains. These bloodstains can be detected using chemical tests. Upon detection, bloodstains can be used to reconstruct crime scenes, as their morphology and geometry can be used to determine information such as angle of impact, sequence of events, and the minimum number of blood releasing events. One underresearched aspect of bloodstain pattern analysis is the interaction between bloodstains and insects. This is somewhat surprising considering that insects an use blood as a food source. The morphology and geometry of a bloodstain can be compromised when an insect uses, or travels through, blood. We are currently investigating the effect of insect activity on the chemistry and gemoetry of bloostains in an effort to increase the relaibility of bloodstain pattern analysis.
