forensic entomology
How is it used in a crime scene?
Entomology is mostly used for calculating the time of death. A forensic entomologist can calculate the time when flesh-eating insects first invaded the body. Fly larvae, once developed and are about to go onto the adult stage, abandon the dead body because their predators are around. This is why by the time a crime is investigated, there may be no insect larvae. But there may be other insects in the area which can provide clues. Some bugs can also be used to see if the body was poisoned because the maggots or larvae would eat the body and at the same time, they would eat the poison in the body. If we know the poison from the body, then we can tell how and when the body died.
Ten Basic Rules for Collection
1. Take good close-up photos of all locations from which arthropods are collected. The state of decomposition can change greatly within hours due to insect activity and weather conditions. Also mite bites should be noted.
2. Since maggots tend to become invisible and “flash out” when photographed, do not use flash photography, especially on digital photos.
A scale in use during training at a mock crime scene.
3. Always use a metric and an inch scale on every picture taken to determine the length of the larvae. The use of international scales is important due to different units of measurement in different countries.
4. Gather one spoon full of insects from at least 3 different areas of the crime scene and the body and place into
3 clearly labelled jars.
5. Do not put insects in isopropyl or formalin. Instead use 98% ethanol for half of the insects collected.
6. Kill the insects with hot water before placing in ethanol.
7. Place half of the specimens in a cool, refrigerated place if available.
8. Label everything excessively with dates, initials, exact times, and locations.
9. Ask an experienced forensic entomologist any questions that arise.
10. Identification must be performed by an experienced entomologist. Keys that are applicable to the local fauna may be used.
Tools Used in Entomology
The following tools are used in forensic Entomology :
Net
Sticky Traps
Vials/Kill Jars
Preservation Chemicals: Ethyl Alcohol and Acetone
Latex Gloves
Forceps
Live Specimen Containers
Shovel
Thermometers
Labels (both adhesive and non-adhesive)
Small Paint Brushes
Foil
Vermiculite and Food
Graphite Pencil
Hand Towel
Camera
Ruler
Paper Towels
Sifting Screens
Death Scene Form