EVIDENCE AND INVESTIGATION UNIT OVERVIEW IN THIS UNIT

EVIDENCE AND INVESTIGATION

UNIT OVERVIEW: IN THIS UNIT YOU WILL SHARPEN YOUR SKILLS IN OBSERVING AND INTERPRETING WHY YOU SEE BY INVESTIGATING EVIDENCE IN HUMAN AND ANIMAL ACTIVITY. YOU WILL EXPLORE AND ANALYZE INDOOR AND OUTDOOR ENVIRONMENTS AS YOU LOOK FOR FOOTPRINTS, MARKINGS, EVIDENCE OF DISTURBANCE AND THINGS THAT ARE LEFT BEHIND. AS WELL, YOU WILL LEARN TO POSE QUESTIONS, DEVISE INVESTIGATIONS, REGONIZE PATTERNS AND DISCREPANCIES, AND THINK LOGICALLY ABOUT WHAT YOU HAVE OBSERVED. ARE YOU READY TO SOLVE CRIMES?

UPON ARRIVING AT THE SCENE OF AN ACTIVITY, THE FOLLOWING STEPS SHOULD BE TAKEN: 1) ASK YOURSELF THE QUESTION: “WHAT HAPPENED HERE? ” 2) BRAINSTORM IDEAS OF WHAT COULD HAVE HAPPENED. 3) INVESTIGATE THE AREA FOR EVIDENCE TO SUPPORT YOUR IDEAS. 4) 5) DISCUSS YOUR EVIDENCE AND INVESTIGATION WITH YOUR GROUP. MAKE A HYPOTHESIS FOR YOUR SCENE THAT SUPPORTS YOUR EVIDENCE.

TOPIC 1 OBJECTIVE: RECOGNIZE EVIDENCE OF RECENT HUMAN ACTIVITY AND RECOGNIZE EVIDENCE OF ANIMAL ACTIVITY IN A NATURAL OUTDOOR SETTING. VOCABULARY: INVESTIGATION: A CAREFUL STUDY OF SOMETHING IN ORDER TO DISCOVER THE FACTS ABOUT IT EVIDENCE: AN INDICATION; A SIGN; THE FACTS AVAILABLE FOR PROVING OR SUPPORTING A NOTION FORENSIC EVIDENCE: TENDS TO SUPPORT FACTS ADMISSIBLE IN A COURT OF LAW

POSSIBLE QUESTIONS TO CONSIDER IN AN INVESTIGATION: • Were these items left in the area recently? • Have they been here for a while? • How can you tell? • Who or what made the prints? • How fast was the subject moving? • What direction was the subject going? • Is there evidence of more than one person or animal being in the area? Did they interact?

TOPIC 2 OBJECTIVE: OBSERVE A SET OF FOOTPRINTS, AND INFER DIRECTION AND SPEED OF TRAVEL.

POSSIBLE DIFFERENCES IN SHOE PRINTS MIGHT INCLUDE: • Comparing lengths and width of prints • Compare variances in the treads of prints • Compare and measure the length of stride • Compare prints made by individuals moving forward, backward, and sideways • Compare prints(depth and distance apart) made when moving at different gaits (walking, running, hopping, skipping, jumping) by different individuals • Compare differences in depth of one print at various points (heel, toe) within the print • Observe overlapping prints • Observe prints made when carrying a weight • Compare prints made under dry conditions versus wet conditions. • Video: https: //www. youtube. com/watch? v=mquy. NZa. Nb. Po

TOPIC 3 OBJECTIVE: • INVESTIGATE EVIDENCE AND LINK IT TO A POSSIBLE SOURCE BY: CLASSIFYING FOOTPRINTS, TIRE PRINTS, AND SOIL SAMPLES FROM A VARIETY OF LOCATIONS • ANALYZING THE INK FROM DIFFERENT PENS, USING PAPER CHROMATOGRAPHY • ANALYZING HANDWRITING SAMPLES TO IDENTIFY THE HANDWRITING OF A SPECIFIC PERSON • COMPARING SAMPLES OF FABRIC • CLASSIFYING FINGERPRINTS COLLECTED FROM A VARIETY OF SURFACES.

FINGERPRINT ANALYSIS • There is a deposit of moisture, salt, and oil on your skin and the ridges of your fingertips. When we touch things, the oil on our fingers leaves a print mark in the pattern of the ridges of our fingerprints. • Solid smooth surfaces such as glass and mirrors will produce the best fingerprints for lifting whereas porous or rough surfaces produce the poorest fingerprints for this purpose. • Deltas help classify the finger prints. A delta is a triangular pattern on the fingerprint. • The 4 most common types of fingerprints are : Loop, whorl, arch, composite.

COMMON FINGERPRINTS • Loop: - The loop is the most common fingerprint type -The ridges enter one side of the print, go up to form a loop, then the ridges exit the same side of the print that they entered -It has one delta • Whorl: - The whorl is like a spiral - The pattern circles around like a whirlpool - It has 2 deltas

• Arch: -The arch pattern of fingerprint is like a wave or a hill. The ridges enter on one side of the print, rise in the middle and exit the opposite side of the print. The arch has no delta. • Composite: - The composite pattern is a combination of patterns such as whorl and arch, loop and arch, or a whorl and a loop.

LATENT PRINTS: • A latent print is a print which is left on a surface and cannot easily be seen. • Solid smooth surfaces such as glass and mirrors will produce the best fingerprints for lifting whereas porous, or rough surfaces produce the poorest fingerprints for this purpose.

RIDGE CHARACTERISTICS • In order for the print to be considered a “match” they must have a number of ridge characteristics in common. • The 4 ridge characteristics to look for in a finger print are: -Bifurcation(fork): One ridge splits to form 2 ridges and then rejoin to one ridge again, forming a shape like a lake. -Ridge Endings: A ridge ends -Island: A very short ridge in the print pattern is not connected to any other ridge, much like an island floating by itself. -Lake: A ridge in the shape of a circle/oval.

TIRE PRINTS Facts to consider when making observations about tire tracks: -location (where the sample was found) -tread width -number of grooves -tread pattern -worn areas -texture Video: https: //www. youtube. com/watch? v=dhk. Sl. Jadf. Ps

CHROMATOGRAPHY • Chromatography is a technique used for separating mixtures, such as pigments in ink. • Capillary Action: The tendency of a liquid to be drawn upward.

FABRIC FORENSICS Man-made fibers: nylon, spandex, rayon, ect. Natural fibers: wool, cotton, silk • What test can be performed to discover what distinguishes one fabric from another. - Will it wrinkle? - What does the weave look like? - How does it feel? - Will it stretch? -Does it absorb or repel water? -What happens when it burns? -What does one thread look like?

GRAPHOLOGY: HANDWRITING ANALYSIS Some indicators used in comparing handwriting samples are: • • • Spacing and slant of letters Spacing of the words Pressure on the page Formation of the loops in the letters, such as “L, O, f, b, p, B”, etc. Dotting the letters of “i, j” Crossing of the letter “t” How letters are joined A combination of printing and writing Formation of less common letters Size of words and letters Extraneous marks on the page Writing tool used • Video: https: //www. youtube. com/watch? v=b. CJLcd 0 j. WGQ

SOIL ANALYSIS • When comparing soil samples, look for differences in: - color - texture - odour -content -particle shape - particle size • Other tests for soil: - Porosity: how much liquid the soil will hold -p. H- soil acidity - Chromatography

TOPIC OBJECTIVE: • RECOGNIZE THAT EVIDENCE FOUND AT THE SCENE AN ACTIVITY MAY HAVE UNIQUE CHARACTERISTICS THAT ALLOW AN INVESTIGATOR TO MAKE INFERENCES ABOUT THE PARTICIPANTS AND THE NATURE OF THE ACTIVITY, AND GIVE EXAMPLES OF HOW SPECIFIC EVIDENCE MAY BE USED