Students at Susquehanna Township High School in Harrisburg, Pennsylvania, participated in a program where the students studied the life cycle of the blowfly and its relationship to the decomposition of a deer. This program motivated 9th grade student Drew Evans to do some further investigation for his science fair project.
Drew was intrigued with the effect that temperature had on the activity of the insects. Knowing that death scene investigations focus on determining time of death based on body temperature and insect activity and that forensic scientists rely on published temperature readings led Drew to this project. He hypothesized that the actual temperatures at a death scene would differ from temperatures recorded by the local weather agencies.
Temperature readings over a 24 hour period
Drew worked with a local game warden to obtain a deer that had recently been hit by a car. Stainless Steel Temperature Probes were placed around the deer: one under the body, one against the body, and one several feet above the deer (to measure the ambient temperature). Twenty-four hour temperature readings were collected on multiple days with the deer located in different locations. The collected data were compared to the temperatures recorded at the local airport and made available through Penn State’s website. Drew found average differences in temperature ranging between 6.1°F (ambient) to 8.7°F (under the deer), which supported his hypothesis.
This investigation has given Drew a better understanding of the difficulties forensic scientists encounter when estimating time of death. Drew was awarded a gold medal for his first place finish in the Earth Science Senior Division of the Capital Area Science and Engineering Fair (an Intel Regional Science Fair).