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Objective: SWBAT describe and lift and latent print. Fingerprint sponge 3 (complete in your composition notebook and record the entry in your table of contents): Write the daily objective Draw an eye, an enclosure, and a fork minutiae. Table of Contents.
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Objective: SWBAT describe and lift and latent print Fingerprint sponge 3 (complete in your composition notebook and record the entry in your table of contents): • Write the daily objective • Draw an eye, an enclosure, and a fork minutiae
Table of Contents 10/16 Fingerprint Sponge 1 35ish Fingerprint notes part 1 35ish Fingerprint exit ticket 1 37ish 10/18 Fingerprint Sponge 2 38ish Fingerprint notes part 2 38ish 10/24 Fingerprint Sponge 3 40ish Fingerprint notes part 3 40ish
Homework • Chapter 6 Review Questions on Quia due Sunday 10/28 by 11:59 pm • Oct. 31 or Nov. 1 Science Fair Research papers are due
Agenda • Two Minute Mystery • Check 1 page summary from when sub was here • Check “Science Fair Proposal Form” and “Background Research Plan” Worksheet” • Fingerprint notes part 3 • Latent Fingerprint Lab • Exit Ticket
Latent Prints Forensic Science T. Trimpe 2007 http://sciencespot.net/
Types of Fingerprints There are 3 types of prints that investigators look for at crime scenes: • Patent fingerprints are visible prints transferred onto smooth surfaces by blood or other liquids. • Plastic fingerprints are indentations left in soft materials such as clay or wax. • Latent fingerprints are not visible but made so by dusting with powders or the use of chemicals. Forensic Science: Fundamentals & Investigations, Chapter 6
Did you know? Camel hair is the most common animal hair used to make fingerprint brushes. Now many brushes (like the one above) are made out of fiberglass. Latent prints are impressions left by friction ridge skin on a surface, such as a tool handle, glass, door, etc. Prints may be collected by revealing them with a dusting of black powder and then lifted with a piece of clear tape.
Magnetic powder can also be used to reveal latent prints. This type of powder works better on shiny surfaces or plastic baggies or containers. Some investigators use fluorescent powder and UV lights to help them find latent prints on multi-colored or dark surfaces. The cyanoacrylate fuming method (often called the super glue method) is a procedure that is used to develop latent fingerprints on a variety of objects. Ninhydrin is a chemical that bonds with the amino acids in fingerprints and will produce a blue or purple color. It is used to lift prints from surfaces such as paper and cardboard. Click the icon to view the Crime 360Super Glue Video Top Left: http://www.stapletonandassociates.com/images/MagPowder.jpg Bottom Left: http://www.ok.gov/osbi/images/ninhydrin%20print.jpg Bottom Right: http://www.forensicsrus.com/images/SupergluePrint.jpg
Fingerprint Forensic FAQs • Can fingerprints be erased? No, if, for example, they are removed with chemicals, they will grow back. • Is fingerprint identification reliable? Yes, but analysts can make mistakes. • Is fingerprint matching carried out by computers in a matter of seconds? No, but the FBI’s Integrated Automated Fingerprint Identification System (IAFIS or AFIS) can provide a match in 2 hours for the prints in its Master File. Forensic Science: Fundamentals & Investigations, Chapter 6
The Future of Fingerprinting • New scanning technologies and digitally identifying patterns may eliminate analytical mistakes. • Trace elements of objects that have been touched are being studied to help with the identification of individuals. • To help with identification, other physical features such as eyes and facial patterns are also being studied. Forensic Science: Fundamentals & Investigations, Chapter 6
Directions: 1 - Cover your table with white butcher paper or newspaper. You must dust everything on the paper! 2 - Get a lifting kit from your teacher that contains black powder, brushes, and clear tape. 3 - Press the pad of your right thumb on the plastic sheet. Place on the paper covering your table. 4 – Dip a brush lightly into the container of black powder and then tap off the extra on the lid. You only need a very small amount of powder to dust the print. 5 – Hold the brush over the print and rotate it between your thumb and fingers. Use the brush to remove any extra powder. 6 - Use a small piece of clear tape to lift the print and place it in on your notecard and label it with your name. CAUTION: The black powder will be messy and isn’t easy to clean up. Don’t dust anything without permission!
How to Dust for Fingerprints • http://www.youtube.com/watch?v=4bBCHByhpF4 What you must have in your notebook: • Lab title “Studying Latent Fingerprints” • Lab Objectives • Your notecard with your lifted print must be taped in the lab • You must write down what type of print it is (arch, whorl, loop)
Clean Up 1 – Clean off the plexiglass sheets and put them back in the kit with the brushes and tape. 2 – Have someone help you fold the paper in half and tap it to return the extra black powder to the container. 3 – Put the black powder in the box and have it checked in by your teacher. 4 – Get a towel and “dry” wash the table – especially the edges that weren’t covered with paper. 5 – Get a wet towel to wash off the table and then wipe it with some dry towels. Keep cleaning until all the black powder is off the table!
Exit Ticket (please complete in your notebook) • What type of print did you lift from the plastic sheet (arch, whorl, loop)? • What are the three different types of fingerprints that can be left on a surface? • Explain how fingerprints can potentially be altered or covered up.