The Telltale Blowfly

How Forensic Scientists Use Entomology to Solve Crimes

Based on the website:http://tlc.ousd.k12.ca.us/~acody/forensic.html

OBJECTIVES• Extracting factual information from text.• Making logical deductions from

information presented.

Introduction Here at CGW Crime Labs, we do our best to

uncover the truth behind a crime by using our science background.

Today we have just discovered the decomposed corpse of a Marine in a rain forest just off the highway in Oahu, Hawaii. By the time entomologist Lee Goff arrived most of the blowflies had come and gone, but many other insects were busy with the body…

Task Your job is to collect and explain evidence on

this murder case and use this evidence to draw a conclusion. You will work in groups of 3 - 4 (with at least one computer per group).

Leader: keep team members on task and focused

Recorder: record all information/dataTime Keeper: keep team on scheduleReader: read all directions and passages

PROCEDURE 1 1. Open up an internet browser. For the full

story on this marine, read the excerpt athttp://tlc.ousd.k12.ca.us/~acody/forensic.html

HINT: You can either copy and paste this link into your browser, or right click on this link and click on ‘open.’

Procedure 2 2. Re-create the table you see below. 3. Fill in the table indicating when the three

insects arrive or leave the body.Type of Insect When they arrive/When

they leaveWhat they prove

Hairy Maggot/Blowflies

Cheese Skippers

Soldier Flies

Procedure 3 Use the example and template on the next slide to

complete this part of the procedures.1. Make a Claim: A conclusion that answers the original

question.2. Give Your Evidence: scientific data that supports the

claim. The data needs to be appropriate and sufficient to support the claim.

3. Give Your Reasoning: a justification that links the claim and evidence. It shows why the data counts as evidence by using appropriate and sufficient scientific principles.

Template and SampleClaim Evidence Reasoning

I. A.

B.

II. A.

B.

III. A.

B.

Claim: Plants are producers in this food web.Evidence: Many arrows point to smaller animals in this diagram.Reasoning: A producer is able to create its own food through a photosynthesis while consumers must eat other organisms to produce energy.

Procedure 4 4. Write a paragraph (5 – 7 sentences long) of your own

explaining when the Marine died, and how you know. Each student is responsible for contributing his/her own explanation. Create a template like the one below.

Student 1 Explanation: Based on my findings, I think that…

Student 2 Explanation: Based on my findings, I think that…

Student 3 Explanation: Based on my findings, I think that…

Student 4 Explanation: Based on my findings, I think that…

Procedure 51. Skim different articles at:http://www.forensicentomology.com/

2. On a clean sheet of loose leaf, answer the following questions. Your responses must be in your own words:

*What is forensic entomology?*What are two examples of how insects help in solving crimes?*Descibe the life cycles that certain bugs undergo. How can knowledge

of insect life cycles aid in uncovering information about a crime scene?

*What types of observations and data should you make and collect (respectively) at a crime scene?

Evaluation 1Claim:0 – Does not make a claim, or makes an

inaccurate claim1 – Makes an accurate but incomplete claim2 – Makes an accurate and complete claim

Evaluation 2Evidence:0 – Does not provide evidence, or only provides

inappropriate evidence (evidence that does not support the claim), no numerical data with appropriate labels

1 – Provides appropriate but insufficient evidence to support claim. May include some inappropriate evidence or missing numerical data or appropriate labels

2 – Provides appropriate and sufficient evidence to support claim. All numerical evidence contains appropriate labels

Evaluation 3Reasoning:0 – Does not provide reasoning or only provides

reasoning that does not link the evidence to the claim.1 – Provides reasoning that links the claim and evidence.

Repeats the evidence and/or includes some scientific principles, but not sufficient

2 – Provides reasoning that links claim and evidence. Includes appropriate and sufficient scientific principles.

Evaluation 4Overall Grade0 – No attempt to start or complete assignment.

Work is missing. Work is plagiarized. Work is inaccurate and does not follow rubric.

1 – Some attempt to participate in project. One missing/incomplete component. A few errors and inaccuracies in responses.

2 – Project is complete and accurate in responses. Follows the rubric.

Conclusion Put the above information together. As a

group, you must decide the following:

1. How long ago did the Marine die? 2. How do you know? 3. What evidence can you use to justify your

claim?

Credits/Resourceshttp://tlc.ousd.k12.ca.us/~acody/forensic.html

http://www.forensic-entomology.com/