FREE online courses on the Basics to Forensic Entomology - Analyzing the
crime scene - Collecting of climatologically data at the scene
When estimating the PMI, climatologically data about the
crime scene is absolutely critical. The length of the insect life cycle is
determined mostly by temperature and relative humidity in the environment
development takes place.
The following climatologically data should be collected at
the scene:
Ambient temperature can be evaluated by taking readings at
0.3 to 1.3 m heights in close proximity to the body.
Ground temperature can be obtained by placing the thermometer
on the ground, immediately above any surface ground cover.
Body surface temperatures should be obtained by placing the
thermometer on the skin surface.
Under-body interface temperature can be obtained by sliding
the thermometer between the body and the ground surface.
Maggot mass temperatures can be obtained by inserting the
thermometer into the center of the maggot mass.
Soil temperatures should be taken immediately after body
removal at a ground point which was under the body before removal. Also take
soil temperatures at a second point 1-2 m away from the body. These temperatures
should be taken at 3 levels: Directly under any ground cover (grass, leaves,
etc.), at 4 cm soil depth and at 20 cm soil depth.
Weather data for the scene should be collected from the
nearest meteorological station. Minimum requirements should be maximum and
minimum temperature and amount of precipitation. Any other information is also
welcome, and may aid in the reconstruction of the events. The climatologically
data should extend back to the time the victim was last seen.
