Day 1: 16 June 2009

Domestic pigs, Sus scrofa, were used in this project as a model of human decomposition. Pigs mimic human remains in their similar intestinal flora, body cavity size, skin composition and hair coverage.

Day 1 consisted mostly of the project arrangement. After measurements of length and weight for each pig were taken, the pigs were randomly assigned to a location and numbered accordingly:

Pigs 1 and 2: University Farm

Pigs 3 and 4: Cleveland State University (CSU)

Pigs 5 and 6: Cleveland State University, to be moved to University Farm after 24 hours

The pigs were placed 50 meters apart, each enclosed with a cage to protect the carcass from large scavengers while still allowing insect activity. A "lean-to" was placed over each cage to limit sun exposure and prevent the carcass from drying out.

Sampling:

During the first 10 days of the study, each pig carcass will be sampled. Observations of the carcasses, decomposition and activity of insects will be made and photographs taken of each carcass to document this process. Readings for ambient, ground and maggot mass temperatures will be recorded in order to determine the growth rate of the insects present on the carcass.


A distinct pattern of insect activity occurs during decomposition , a process called succession. By collecting samples of the insects present during the different stages, it is possible to determine the pattern of succession on the pig carcasses in the urban and rural settings.


What insects are collected:

Adult flies are captured with an aerial sweep net. Beetles and maggots are collected with forceps and saved for preservation and rearing. Blow flies can readily detect decomposition and often arrive within minutes or hours after death to lay their eggs. Maggots are of great importance but are more difficult to identify than adult blow flies. In order to determine which species are present, maggots are collected for preservation and rearing. The process of rearing involves collecting maggots from the carcass and placing them in a container with raw beef. The beef is wrapped in damp paper towel and aluminum foil and placed on top of saw dust. When the maggots have matured to a post feeding stage, they will move off the meat to bury themselves in the saw dust to pupate. When the flies emerge they will be collected, pinned and identified.

Pig 1. Location: University Farm

Pig 4. Location : CSU. Note the abscess on hind leg.

Pig 6. Location: CSU, to be moved to farm.

Submitted by Krystal Hans, MS student, Cleveland State University, 30 June 2009

Invertebrate Signature on Moved Pig Carcasses

Insects are of great importance as evidence in a human death investigation due to their ability to quickly inhabit a corpse and arrive in a recognizable pattern of stages during the decomposition process. Forensic entomology is the utilization of insect evidence in investigations, mainly violent crimes.



The question of movement of a body frequently arises during investigations. This thesis project explores the presence of an insect signature associated with a moved corpse. The carcasses of 6 domestic pigs destined for euthanasia were acquired and placed at the following locations:

2 in a rural setting at University Farm(Case Western Reserve Research Farm) in Hunting Valley, Ohio.

4 in an urban setting on the campus of Cleveland State University in downtown Cleveland, Ohio.

After 24 hours, 2 of the pig carcasses from the urban location were moved to the rural location to imitate the movement and disposal of a body to a secluded area after a violent crime has occurred.



The 6 pig carcasses will be sampled over the summer in order to collect the insect "evidence" from each body. This project will examine the insect composition at each location to see if an insect signature is in fact associated with a body moved from an urban to a rural area.



Pictures, video and text will be uploaded throughout the decomposition process.


Submitted by Krystal Hans, MS student, Cleveland State University, 29 June 2009