Forensic Entomology By Trey Jackson

INSECTS AND CRIME COMBINED!

What is Forensic Entomology?

• Forensic entomology is the application and study of insect and other arthropod biology to criminal matters. The use of insects in this practice is very interesting.

What They Look For

• Forensic Entomologists try to determine the try and determine the "PMI", the postmortem interval, or time that elapses between death and corpse discovery. They also are able to see if the body was moved from one location to another. I.E. – “An Ohio man who claimed to have been in Ohio on the date his wife and children were murdered in California was found to have grasshoppers and other nocturnal insects from the west on his car grille, indicating that the car had been driven at night to the western US, and he was subsequently convicted.”

Blow Fly Cycle (and Others)

• Forensic Entomologists look at what stage of the blow fly life cycle is occurring on the corpse, for this will give a very good estimate on how long the body has been there.

• BUT this can be tricky due to environmental factors effecting the insects.

Entomology Process

Blow Fly Life Cycle

Techniques w/ Blow Fly Cycle

• The forensic entomologist can use a number of different techniques including species succession, larval weight, larval length, and a more technical method known as the accumulated degree hour technique which can be very precise if the necessary data is available. Will provide evidence to support how long body has been at the scene, and if it has been moved.

Environmental Effects

• The environment has a huge bearing on how fast or slow insects will begin the process, and this includes on what region the body is in.

• For instance insects will colonize a body slower in a desert than in a forest, and bodies dumped underwater sometimes don’t receive any colonization. Also in extremely cold environments insects are less likely to colonize quickly.

Environmental Growth Chart

Re-Simulate Conditions

• In order to confirm observations on site, the crime scene is re-simulated with similar conditions that the body was found in.

• Sometimes re-simulating conditions can occur in a lab, but it can also be performed in fields using pigs as the subject.

• However, if there are very specific conditions that must be met though it will generally be done in the lab.

Interview/Case

• In Word Document