Do Now: Update your exit ticket tracker! 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? Objectives:Students will be able to compare and perform fingerprint detection techniques. SWBAT describe the historical and current methods for fingerprint matching.

Announcements Exit ticket trackers up-to-date 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 AFIS AFIS Head Nod

SWBAT describe, compare, and perform fingerprint detection techniques. SWBAT describe the historical and current methods for fingerprint matching Objective Check:

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 IodineIodine- 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 2. The chemicals used to develop latent prints reacts with the _______ left by your fingers. (may be more than one answer) 3. Describe the history of the fingerprint system.