Transcript Bricklayers and Secretaries- tends to wear down ridges work with lime

Objectives: Students will be able to compare and perform fingerprint detection
techniques.
SWBAT describe the historical and current methods for fingerprint matching.
Do Now:
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1.Explain the history of the fingerprint system so far.
(Bertillonage system to Henry classification system)
2. What is the difference between a latent, plastic and patent
print?
3. Why might a detective need to use a power test on a
crime scene?
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 Quiz on Tuesday
 Homework due on Tuesday

Exit Ticket
1.
Raised portions on your hands that allow
for gripping:
a.
Fingerprint
b. Whorls
c. Friction Ridges
2. Define basal layer.
3. If 65% of fingerprints have
loops, how are fingerprints
considered individual evidence?
Review
Finishing the unit: Why are we learning
about fingerprints? What does that have
to do with Forensic Science?
Fingerprints
Patterns
Minutiae
Types of fingerprints
History
Erase your fingerprints
Bricklayers and Secretaries- tends to
wear down ridges
 work with lime [calcium oxide] – base.
dissolves the top layers of the skin. The
fingerprints tend to grow back over time.

Why would the Henry Classification System
fail?
But FIRST
CFU:
The Henry Classification System uses:
a. The amount of whorls on your index fingers
to calculate a number
b. The presence of whorls on all ten fingers to
calculate a number
Turn and Talk: Why would the Henry
Classification System fail?
AFIS
Automated Fingerprint Identification
System
Modified Henry Classification system
System
A better method of storing, retrieving, and
matching fingerprints using 10 print
system
Digitally encodes fingerprints
0:30- 2:11

Head Nod
AFIS
Objective Check:
SWBAT describe, compare, and
perform fingerprint detection
techniques.
SWBAT describe the historical and
current methods for fingerprint
matching
CFU:

T/F: AFIS is similar to the Bertillonage
system, in which both systems uses
measurements of key features (i.e. height,
diameter of head)
Fingerprint Detection Techniques
Powder Testing– powder attaches to oils
Iodine- attach to oils from fingers
Ninhydrin - reacts with amino acids (proteins)
Silver nitrate- reacts with salt
Objective Check:
Students will be able to describe, compare, and
perform fingerprint detection techniques.
Lab
1. Partner 1/Partner 2 …..Partner 3
 2. Start with Silver Nitrate (no spills)
 3. Plastic Print- turn in
 4. Dark powder- chocolate allergy??...baby
oil
 5. Post lab questions- 2 hand writing

Objective Check!

Students will be able to describe,
compare, and perform fingerprint
detection techniques.
Exit Ticket
1.Visible prints left by a finger that has touched
colored material such as blood or paint is called
A. Latent B. Patent
C. Plastic
D. Paint

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2. The chemicals used to develop latent prints
reacts with the _______ left by your fingers.
(may be more than one answer)
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3. Describe the history of the fingerprint system.