What is the main role of a forensic entomologist in a criminal investigation?

To estimate the post-mortem interval (PMI) using insects found on or near a body.

What does PMI stand for, and why is it important in forensic investigations?

PMI stands for post-mortem interval. It is important because it helps determine the time since death, which can provide alibis or destroy them, and focus the investigation.

Why are traditional methods of determining time of death, such as rigor mortis, algor mortis, and livor mortis, less reliable after 72 hours?

After 72 hours, the body begins to decompose, making these signs less reliable. Insect activity becomes a more accurate indicator.

How do forensic entomologists use the life cycle of flies to estimate the time since death?

By analyzing the developmental stages of flies (egg, larva, pupa, adult) and considering environmental factors like temperature, entomologists can backtrack to estimate when the insects first colonized the body.

Explain how temperature affects the development of insects and how this is considered when estimating PMI.

Insects develop faster in warmer temperatures and slower in colder temperatures. Forensic entomologists must consider the temperature at the crime scene and the body temperature to accurately estimate the insect development rate and PMI.

Forensic Science and the Heart

8th GradeScience90 min

Learning Objective

I can describe how forensic scientists analyze heart-related evidence in criminal investigations.

Lesson Flow

Watch Video

7 min

How Entomologists Use Insects to Solve Crimes | WIRED

WIRED

Guided Notes

18 min

Key concepts students will learn:

•
Forensic entomologists use insects as "tiny witnesses" to help provide justice to victims by analyzing insect activity on and around a body.
•
The post-mortem interval, or PMI, is the time between the moment of death and the identification of a dead body.
•
Estimating the PMI relies on analyzing the life cycle of flies and other insects, as their development from egg to adult can be predicted based on environmental conditions such as temperature.

Practice

27 min

12 questions • Multiple choice & Short answer

Exit Ticket

5 min

“Name two factors that forensic entomologists consider when estimating the post-mortem interval (PMI) using insect evidence.”

Teacher Guide

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Answer keys for all questions
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Forensic Science and the Heart

Learning Objective

Lesson Flow

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Guided Notes

Practice

Exit Ticket

Teacher Guide

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