Lesson Plan (Forensic Science – Decomposition)
Name: Benjamin Unger
Mentor Teacher: K. Wardell-Stone
Date: 01 Oct-18 Nov 2014
Partner:
School: Southfield High School
Part I: Information about the Lesson or Unit
Unit: Mechanisms of Death/Determination of C.O.D (Cause of Death)
Topic: Decomposition
Type of Class
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Grade level(s): 10 11 12 elective/high track
Type of school: Urban/Suburban
Tracking level: Untracked
Abstract
Fundamentally, the concept of ‘Forensic Science’ can be defined as the application of
scientific concepts and principles to the solving of crimes. The usage of these principles must be
in a specific and legally-accepted mechanism, which permits both wide-scale understanding as
well as appropriate reproducibility. Here, we are examining in a small-scale model how various
materials (plants, animal components, etc) decompose in a controlled environment. This both
mirrors how forensic researchers examine the role of environmental factors in human
decomposition (U of Tennessee Body Farm: http://video.nationalgeographic.com/video/bodyfarm-sci), and allows detailed examination of those factors (forensic entomology, phases of
decomposition, etc). Students will plan, assemble and maintain their decomposition chambers for
no less than eight week, and then construct a detailed report demonstrating how their chosen
items decomposed, and relate these changes to the biological, chemical, and environmental
changes which occur in a decomposing body.
Part II: Clarifying Your Goals for the Topic
Because this course is an elective, there are no ‘required concepts’ that must be taught. However,
I feel that this freedom offers a unique opportunity to blend together nearly every other scientific
discipline – chemistry, biology, earth science, physics, etc., all play a key role in the application
of forensics to resolving crime. As a consequence, I define student-centric, high-level exercises
and couple them with NGSS cross-cutting concepts. In particular, I consistently reinforce the
idea of scientific inquiry in a system:
“In grades 9-12, students investigate systems by examining the properties of different
materials, the structures of different components, and their interconnections to reveal the
system’s function and/or solve a problem. They infer the functions and properties of natural and
designed objects and systems from their overall structure, the way their components are shaped
and used, and the molecular substructures of their various materials.” (NGSS Crosscutting
Concepts, p. 10). Further, the NGSS defines several general objectives which are designed to
ensure ‘college and career readiness’, through blending practices, concepts and core ideas.
Knowledge: Big Ideas
Decomposition is a complex process. Besides the ‘big three’ methods of determining Time of
Death (Alvor Mortis, Rigor Mortis and Livor Mortis), scientific research has focused on the role
of the larger ‘environment’ in body decomposition. Using factors such as insects (forensic
entomology), plants (forensic botany), environmental (outside temperature, humidity,
predatory/scavenging animals) and even the method of body disposal (carpet, tarp, etc), we will
examine how the decay process can change in a predictable and defined manner.
Knowledge: Observations, Patterns, and Models/Principles
Students will be tasked with formulating a hypothesis and structure for their decomposition
construction. As seniors, these students are expected to have had some experience researching
and constructing a research plan; they will do so, and be required to explain this plan prior to the
beginning of the construction process. While this is ongoing, students will explore the processes
related to the determination of T.O.D in order to understand some of the underlying behaviors
behind decomposition of human bodies.
Experimental Observations: Students will be given the following rubric to define their
observation patterns. 2x/week, students will be given 5-10 minutes to enter this information in
their notebooks along with photographic evidence as necessary.
Reference Card
1) Place all observations in your forensics notebook. Use a new page for each observation.
Include date, time, and approximate conditions (is it cold in the room, do you think the
chamber has gotten sun recently, etc, etc)
2) Use your observation skills. Examine the bottle carefully, looking for smells, sights, sounds, and
changes since your last examination. Pay close attention to the following:
a. Moisture
b. Mold
c. Evidence of major changes/structural alteration in the bottle contents
d. Pressure changes
e. Odor
f.
Color
g. Temperature (is the bottle warm or cold to the touch? Does this fit with your expectation
based on the air temperature?)
h. Insect Life or changes in insects
3) Note if you have made changes – added water, or other modifications
Practices: Objectives for Student Learning
Objective
Michigan Objective(s)
Type
1. Construct and revise an explanation based on valid and reliable evidence obtained from a
variety of sources (including students’ own investigations, models, theories, simulations,
peer review) and the assumption that theories and laws that describe the natural world
operate today as they did in the past and will continue to do so in the future. (HS-LS2-3)
2. Design, evaluate, and refine a solution to a complex real-world problem, based on
scientific knowledge, student-generated sources of evidence, prioritized criteria, and
tradeoff considerations. (HS-LS2-7)
Using SP
Inquiry
Using SP
Inquiry
Specific Lesson Objective(s)
1. Using appropriate scientific resources and accepted practices, design a decomposition
chamber to monitor the decay of specific, appropriate items. Predict the fate of those items
over specific time periods, and support this prediction with available information.
2. Over the course of several weeks, observe and catalog the changes to your
decomposition chamber. Using precise, scientific language, compare your predictions to the
result over time and relate these changes to colleagues.
3. Collate and present your data outward to others in a scientifically appropriate manner.
Justify your predictions, and explain sources of difference in predictions as well as possible
sources of error. Understand and explain how different environments can result in changes
in overall decay, and relate this to forensic determination of time/mechanism of death.
Part III: Classroom Activities
Resources
Source and description of resource
http://www.bottlebiology.org/investigations/decomp_main.html
This is the website which provides the instructions for
assembling and loading the decomposition bottles.
Beyond The Grave – Understanding Human Decomposition
(http://www.archeo.uw.edu.pl/zalaczniki/upload617.pdf)
Arpad Vass assembles a unique high-level article explaining
the methods and mechanisms of human decomposition (re:
Body Farm), using pictures and complicated text. Excerpted
Possible uses for
your lesson
Printouts will be
provided to help
students with
construction process.
Article will be
provided as a source
of information for
students to think and
plan their
decomposition
Strengths and
weaknesses
Reinforces engineering
design and cross-cutting
concepts; however, the
details are less than
specific and the
assembly instructions
are not entirely clear
(note: for this sequence,
I have given extra time
for students to decipher
and plan the
construction to help
mitigate this).
Reading level and
comprehension is key in
NGSS core standards.
Exposing students to
primary/secondary
literature sources is also
from ‘Microbiology Today’.
projects.
Student-Provided Websites/Videos discussing material
decomposition
Students were
instructed to bring
their own sources to
explain why they
chose certain things
for their
decomposition
chambers.
key to developing
research and study skills
for college or career.
This depends on student
motivation (and
technology availability).
However,
accommodations were
made to help students
with accessibility
problems complete the
project.
Materials
Plastic Bottles
Various Organic Material (depends, per student)
Soil (provided)
Tape
Cleaning Supplies (provided)
Activities
Day 1: Introduction (students will have already had a discussion of human decomposition in
terms of the stages involved, as well as how organic and inorganic forces can act on a
decomposing human body). Processes such as saponification, mummification, or dehydration
will also be introduced as a possibility, both in humans and in our model columns. These were
also covered in a separate assignment (see decomposition assignment #1).
Day 2, 3: Students will continue planning and designing decomposition chambers. Along with
this, each group will produce a poster, pictorially predicting the phases of decomposition for the
various items in their decomposition chamber over increasing lengths of time. These posters will
form the basis for prediction for the final assessment.
Day 4: Students will assemble their decomposition columns. Material will be provided, but
students will be encouraged to bring and add pre-approved items from home. Once the bottle is
complete, students will photograph it and take initial observations (following directions above).
Day 5-?: Students will observe no less than 1x (2x preferred)/week on a pre-determined
schedule. This gives students ‘ownership’ of their project, but also places responsibility for
tracking and maintenance to them in terms of handling and managing long-term projects.
Final Day: For the final observation, students will be given the opportunity to compare to their
initial observations, and we will discuss the assessment task (clarified below). Each group will
compile their shared observations, but submit individual reports.
Part IV: Assessment of Students
Assessment Task
Report Outline
For this assignment, you will be tasked with detailing and explaining the phenomena you have
observed in your decomposition bottles over the past several weeks. The assignment consists of
two parts:
Part 1: Due November 14
Using your composition notebook and recorded data, re-write your observations into a coherent,
typewritten form (12 point font, 1” margins). For each day, include:
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Date of observation
Time of observation
Notable characteristics (smell, color, etc)
Anything you noted that was peculiar? Were there questions?
Did you do anything on this day? (water, move, etc?)
For the first entry, make sure you tell me how you put together your composition bottle.
This may be done as a group process, but each person should submit their own copy. I
strongly suggest that you incorporate your photographs as well, because this will make
your task easier later on (see below).
Part 2: Due November 24
Using your completed, well-formatted notes, write a paper of no less than 1500 words describing
the process of decomposition occurring in your bottle. You are to follow the same rules as above
(12 point, 1” margins). In addition, you will be expected to use at least five references (5) in
your report, discussing how other scientists observe decomposition, and how they might predict
the contents of your bottle would decompose. Be sure to incorporate photographs into your
paper that you took of the project. Each photograph should include a date and time as well
as total elapsed time of decomposition (estimated, if necessary)
Remember to consider the following:
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What is in your decomposition bottle?
Why did you use those particular items?
Temperature, humidity, organisms that were present
How did the results compare to your prediction poster?
If you were to repeat the experiment, how would you change it?
What interesting things happened that you didn’t expect, and how would you explain them?
How did the items in your bottle decompose? Use photographic evidence to explain.
Be sure to include a list of your references!