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Laureen Botticelli May 19, 2004 Lesson Plan Intro to forensics Goal: The purpose of this lesson is for students to understand what forensic science is and learn about fingerprinting. The activity is to have students learn how to make a fingerprint and classify fingerprints based on the pattern on the print. The use of ink from a pad (though it can be messy and difficult to clean off hands) is the simplest method for making fingerprints To simplify the classification of fingerprints there are four major categories to consider: loop, arch, whorl and accidental. Using these four categories students should be able to identify their fingerprints. Introduction: (Teachers Notes) I. What is Forensic Science? Forensic Science is any aspect of science as it relates to the law. Typically, it includes the disciplines listed below, but just about any area of science could be called into question in a court of law. II. Firearms and Toolmark Identification. Firearms examination involves the identifying characteristics between firearm and projectile, projectile and target. Typically, this includes matching bullets to the gun that fired them. Toolmark identification involves the identifying characteristics between tools, such as a pry bar, and the object on which it is used, such as a door frame. Also included in the category are explosives and imprint evidence. Forensic Psychiatry and Profiling. The first category involves mental illness and disorder, what creates mental illness and disorder, and its diagnosis and treatment. The other category involves profiling, in which an investigator can examine certain crime scenes to come up with a personality profile of the offender. Questioned Document Examination. This discipline involves all special relationships that may exist between document and inscription and how it relates to a person or sequence of events. This includes forgery, counterfeiting, handwriting analysis and other related subdisciplines. Criminal Law. Criminal Law serves to define offenses under a codified system of laws and punishments. Basically, it is where we define what a crime is and how it goes about being prosecuted. This section contains a bullet list of offenses and what constitutes each offense. Personal Identification. The name is self-explanatory. This involves how an individual can be identified to the exclusion, or at least to the smallest percentage of the population, of all others. Includes fingerprints, dna analysis, odontology, and a number of other subdisciplines. Forensic Photography. Basic techniques of photography as they apply to investigative work. And a couple of neat tricks. Crime Scene Processing. This includes all aspects of forensic science and how they come together when searching a crime scene, collecting evidence, tagging and bagging evidence, and analyzing evidence in the lab. Careers in Law Enforcement. What's out there, what you need to get there, and what's in it for you. Student Handout: Cont. Fingerprints There are three basic fingerprint patterns: Loops, Arches and Whorls. Everyone falls into one of these three patterns (diagram). Within these patterns are what we call minutia points. There are about thirty different types of minutae points, and no two people have the same types of minutae in the same number in the same places on their fingertips. This is why our fingerprints are totally unique. Your fingerprint patterns are hereditary. They are formed before you are born, while you are still in the womb, they never change through out your lifetime, and they are even around for awhile after you die. So, why are fingerprints so good for identification purposes? They are totally unique, and they never change. Your fingerprints are formed underneath your skin in a layer called dermal papilae. As long as that layer of papilae is there, your fingerprints will always come back, even after scarring or burning. Gloves don't necessarily help you from leaving fingerprints. Surgical gloves were made to keep surgeons from infecting their patients. You can actually leave prints through surgical gloves. Surgical gloves were made to keep sterile conditions during operations. They have to fit like a second skin for surgeons to be able to pick up their instruments. They fit so tightly that fingerprints 'pass through' the latex membrane. They can also be turned inside out to yield fingerprints from the inside surfaces. Leather gloves can be treated in the same manner. Also, leather gloves can leave a print that is unique to that glove and no other (leather comes from cow skin, which is just as random as human skin). Even cloth gloves, such as mittens, can leave a distinctive print that can be traced back to the mitten that made it. Prints are left on a surface because we are constantly secreting water and body oils and other compounds through our pores. This material is left on the surface we touch in the form of a fingerprint. Different surfaces require different techniques for developing prints. In the movies, you usually see detectives with brushes. They are powder processing the prints. Minute particles of powder cling to the print residue as the brush passes over it. The print is then lifted with tape. Another process involves fuming. Vapors of iodine and superglue (bonds in seconds) will coalesce inside the print residue to reveal a latent print. Try this at home: You will need a zip lock baggie, a tube of superglue (i've found the gel version works a little better) and a can of soda or drinking glass. Place the can or glass in the zip lock baggie. Lay the baggie flat on the counter. Squeeze out a generous amount of superglue into the baggie (don't glue the glass to the baggie). Seal up the baggie. If you can, blow some hot, moist air into the baggie, like when you're trying to fog up a window with your breath. Seal it tight. The vapors from the superglue will build up in the tiny zip lock atmosphere and creep up into the prints on the glass or can. There, they will crystallize and, after awhile, you should see starchy white fingerprints develop on the glass or can. There are special processes that develop prints on paper, wood and cardboard. Fingerprints can be developed on objects that have been in water. Prints can be developed off of skin (such as from the neck of a strangulation victim). There are very few surfaces on which a print cannot be developed. Computers have revolutionized the techniques used to match fingerprints. Until recently, the old standard was the Henry Classification System; a cumbersome sequence of letters and numbers broken down into several levels of classification. It could take weeks, sometimes months to compare a suspect fingerprint to a department's print files. The advent of digital technology has changed all of that. Prints can be image scanned directly into a computer, doing away with ink and fingerprint cards. Prints can be compared at a rate of 400,000 per second. You couldn't do that in your lifetime. It's called AFIS. Automated Fingerprint Identification System. Departments will input all the prints from arrests and all of the print cards they already have on file to create an historical record. They also input all of the prints from any unsolved crimes, in the hope that a hit might come up from a routine arrest. Local departments are linking their systems into a national database. The FBI wants national standards and a fully functional national network in place by the year 2000. With a national network, you could get busted in New York and have a print hit come up from a crime you committed in California. STUDENT ACTIVITY NOTES Part 1 of the procedure has students taking their fingerprints and recording then on their chart. The emphasis should be on a clear print for each finger. Students will not be able to properly classify their fingerprints if the prints are not taken properly. In Part 2, a scenario is given to the students. They must compare the collected fingerprint to several possible suspects. You will have to collect a series of fingerprints for use in this part. Your colleagues would be a good source of prints. With each activity there is an attempt to contextualize the scientific skill or process the students have developed. This provides them with a opportunity to demonstrate what they have learned. You may decide to assign the questions in this or any other activity or you may decide to have a debriefing of the activity that includes a discussion on the questions. If you decide to have the students keep a forensic database or forensic log book, then you may want the students to write a paragraph, that encompasses the questions, reflecting on what they did today. MATERIALS Stamp Pads (preferably with washable ink) Activity Objectives During this activity you should be able to: Take your fingerprints and classify them according to the patterns of loop, arch, whorl and accidental Use this fingerprint classification system to match an unknown fingerprint to a series of known samples Procedure Part 1 - Making and Identifying Fingerprints There are many methods of taking fingerprints, but using ink pad to make fingerprints is a common method. Please follow the procedure below. Make a fingerprint record chart similar to the one shown Roll your right index finger lightly on the ink pad, then roll the inked finger onto the space in your chart (you may have to practice this technique until you can produce a legible fingerprint). Repeat this method for each finger on your right hand Examine each print and identify its pattern. Record this information on the chart. Part 2: Identifying an Unknown Fingerprint Obtain a copy of the fingerprints left by an unknown person on the teacher’s lunch box. It is assumed that this is the person who ate the teacher’s sandwich yesterday. Obtain a copy of the fingerprints of the possible suspects Classify the unknown fingerprint and the fingerprints on the possible suspects Based on your classification data, conclude, with supporting evidence, which of the possible suspects ate the teacher’s sandwich. Reflections on the Activity Answer the following question in your crime lab book 1. Explain how you would use fingerprints collected from the scene of a crime to identify a suspect.
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