Document Analysis
When a document has been exposed to fire or excessive heat it becomes dark and brittle. This is known as a __________________?
Charred Document
Someone's walking habit is known as their ______.
Gait
A mark or impression made by a tool when it is pressed against a softer surface is a(n) __________.
indentation
What is the statistical breakdown of the 3 main fingerprint patterns?
Loops: 65%
Whorls: 30%
Arches: 5%
At what age range do most people develop their 3rd molar?
17-21
Name and describe one of the 12 handwriting traits
Define Dentition Pattern
The individual pattern made by a set of teeth
What are the 3 types of tool marks?
Abrasions
Indentations
Cutting Marks
When are fingerprints formed?
What chemical is used to make a blood visible even after it has been cleaned up?
Luminol
What is the difference between obliteration and erasure?
Smearing over or blotting out the original text on a document is considered obliteration.
Using abrasive instruments or chemicals to remove the writing is erasure.
What is the difference between enamel and dentin?
Enamel - hard outer covering that protects the tooth
Dentin - similar in composition to bone and is made of calcium and phosphorus (when we don't get enough calcium at a young age, our teeth can rot when we're older)
What is the purpose of rifling?
Rifling is when the barrel of a firearm has spiral grooves. It is used to spin the bullet and therefore stabilize it as it flies through the air.
What are the regional and federal fingerprint databases called? Give me the name and the acronym.
In your answer be sure to indicate which is regional and which is federal.
Automated Fingerprint Identification System (AFIS) - Regional
Integrated Automated Fingerprint Identification System (IAFIS) - Federal
What is the difference between wheelbase and track width?
Wheelbase measure the car from the center of the front axle to the center of the back axle.
Track width measures how wide the vehicle's axles are.
What is the difference between and exemplar and a questioned document?
Exemplar - authentic/original handwriting sample
Questioned Document - a document that is part of an investigation
Skid - Can tell us how fast someone was going when they applied their brakes.
Yaw - Can tell us the person was traveling too fast around a curve and lost control of their vehicle
Tire Scrub - Can tell us where an impact occurred
A hammer can be considered either class or individual evidence.
Describe how a hammer can be considered individual evidence. Describe how a hammer can be considered class evidence.
Brand new off the shelf, the hammer is considered class evidence because it is just like all the other hammers on the shelf.
As the hammer is used, small scuffs and marks become present on the hammer. Those unique marks vary for every hammer because everyone uses their hammer differently.
What is the difference between an ulnar and radial loop? Use your marker to draw the radial and ulnar loops on one of your team members.
Ulnar loops have an opening that open/point toward the pinky finger.
Radial loops open up to the thumb.
What is the Misinformation Effect and how might it affect a criminal investigation?
When you are asking someone to recall something from memory and you lace false details into those questions. This may cause someone to remember something that wasn't actually there.
List the 12 handwriting traits.
Line Quality, Spacing, Size Consistency, Continuous, Connecting Letters, Letters Complete, Cursive & Printed Letters, Pen Pressure, Slant, Line Habits, Fancy Curls & Loops, Placement of Dots & Crosses
Name & describe the 3 types of impressions and how to analyze them.
Latent (invisible) - Dusting then photography, followed by electrostatic or gel lifting
Patent (2D, visible) - Photograph impressions
Plastic (3D) - Take pictures, create a cast
Define and provide an example of each of the 3 types of tool marks.
Abrasions - when 2 surfaces slide past each other
Indentation - when a tool is pressed against a softer surface
Cutting - marks produced along the edge of a surface as it is cut
What are the 3 main fingerprint patterns?
What are the two ways used to describe each of those 3 patterns?
Loops: ridgelines enter and exit from the same side, 1 delta
Whorls: circular pattern, 2 deltas
Arches: ridgelines enter and exit from opposite sides, look like hills/mountains
What are the 7S's in order?