Test 10: Document Analysis, Forensic Engineering, Cyber Crimes, Forensic Psychology

Handwriting Analysis

• Forgeries

• Window to personality

  • Psychological profile

• Individualistic

Handwriting Traits

• Shapes of the letters and their slant, angles, connections, and curves

• The line quality, or the thickness of the line as a result of the type of writing instrument used and the pressure exerted while writing

• Spacing, alignment, formatting, and unique punctuation

• Spelling, phrasing, punctuation, and grammar

Handwriting and Personality

• Heavy pressure = strong emotions

• Light pressure = not much emotional or physical energy

• Left slant = tries to avoid emotional situations (cold, indifferent)

• Right slant = emotionally responsive (caring, warm)

• Vertical Letters = cool-headed

Imaginary Line Writing (Slant Upward)

• Straight = tense, over-disciplined

• Very wavy = emotional rollercoaster

• Slant upward = optimism

• Slant down = pessimism, depression, tired

Paper

Mat of roughed up fibers; made of cotton or linen and wood fibers

Before Paper

Egyptians used mashed, lased, papyrus plant (3000 BC) or clay bricks or skins

Paper Analysis - Watermarks

• Can tell the age of the document

• Can tell manufacturer and location of store selling paper

• Object to displace pulp during sheet formation

• Area of thinner paper - can see light through

Safety Measures on US Currency

• Copper to green color shift when bill is tilted

• Watermark

• Security thread

• Microprinting

Iranian Missile Test Image

Fake

• two missiles were cloned and added to the image

• repeats in smoke patterns

• cloning is also used in movies to make it appear that there are more people in the frame than there really were

Specular Highlights - Twinkle Science

• depending on where the light source is coming from, the light hits the eye differently

• if an image is altered, the specular highlights on two people may not match

Geotagging

Photography applications may save the location that an image was taken with the photo

Voice Analysis

Unique voice production to an individual is based on the physical processes of speech itself

• nasal cavity

• lips

• jaw

• tongue

• palate

• oral cavity

• pharynx

• epiglottis

• pharynx-larynx opening

• larynx

• esophagus

Voice Prints

• electronic representation of voice

• recorded on a spectrograph

Possible Causes of Single-Vehicle Accidents

• Distraction (phone, radio, bugs)

• Drunk

• Excessive speed with loss of control

• Slick road surface (unsafe speed, unsafe distance, bald tires)

• Avoidance of animal, person, or other vehicle

• brake/accelerator confusion

• Equipment malfunction

• Asleep

Skid Marks

• Evidence of braking before crash

• Friction between road and tire causes burning

• Can determine Minimum Traveling Speed preceding accident, site of incident, evidence of avoidance or lack of avoidance

Antilock Breaking System (ABS)

results in short, disconnected skid marks

Skid Marks - Minimum Speed

• Simplistic skid-to-stop formula

• Assumes final velocity is 0 mph (gently comes to a stop with no impact)

• S = √(30Df)

• S is speed in mph

• D is skid distance, in feet

• f is drag factor (includes grade considerations, braking efficiency, and coefficient of friction)

  • f = Coefficient of Friction x Braking Efficiency + slope

Friction Table (Estimates)

• Concrete: 0.75

• Wet Concrete: 0.60

• Dry Asphalt: 0.65

• Wet Asphalt: 0.50

• Wet Grassy Field: 0.20

• Gravel and Dirt Road: 0.35

• Ice: 0.10 to 0.15

• Snow: 0.20 to 0.25

Best Ways to Determine Real Coefficient of Friction

• Optimally, use subject car and run at known speed

• Create skid marks

• Calculate coefficient of friction

• Or use Drag Box

  • Box has weight

  • Box has tire surface on bottom of box

  • Measure force to pull box and maintain speed

  • Coefficient of friction = average pull force/box weight

No Skid Marks

• Brake malfunction

• Not watching road

• Couldn’t see out window

• Drunk 

• Unconscious

• Event Data Recorder

  • Logs pre-crash speed

  • Logs brake use

• Can look at Victim’s Crush Depth

  • Depth depends on car type

  • About 20in for every 35mph

  • V = (V₀ + k)D

  • V is impact speed

  • V₀ is the max speed for no crush (manufacturer)

  • K = crush stiffness (manufacturer)

  • D = avg Crush Depth (measured)

Lights

• Brake lights have filaments bowed upward

• This means lights were on at crash

• Heat and impact causes deformed shape

• Means that driver braked before crash

• Horizontal filaments tell of lights not being on at crash

Inherent Problems with Data

• Size/volume

  • Terabytes of data (~10-20 TB = Y2K Lib. of Congress)

  • Computers store 100s of thousands of files - in thousands of file types

  • Data is simultaneously in multiple contexts

• Volatility

• reliability/authentication

• Content

Forensic Psychology

Courtroom Uses

• Jury Selection - Voir Dire

• Competency for hearings

• Custody cases

Voir Dire - French for “to speak the truth”

• Process through which potential jurors are questioned by either the judge or a lawyer to determine their suitability for jury service

• The preliminary questioning of witnesses to determine their competence to testify

  • Ask open questions

  • Repeat the words the juror uses

  • Give verbal and nonverbal cues to keep jurors talking

Investigational tools

• Polygraph and brain-fingerprinting

• Hypnosis

• Profiling

Tasks of Forensic Psychologists

• Testing for mental illness

• Assessing suspects’ sanity

• Establish mental state at time of crime

• Competency to stand trial

• Detect signs of deception and malingering (fake illness)

• Profiling perpetrators

“Disputed” Techniques

• Brain fingerprinting

• Lie detector

  • Control question

  • Directed lie

  • Guilty knowledge test

• Hypnosis

Motivations Behind Arson

• Vandalism

  • Juvenile lower class

  • Afternoon

  • Weekdays

  • Up to grades 6-8 education

  • Lives close

  • Stays at crime scene

• Excitement

  • Juvenile middle class

  • Afternoon

  • Lives alone

  • Lives close

  • Stays at crime scene

  • Up to grade 10 education

• Revenge

  • Adult lower class

  • Afternoons

  • Weekends

  • Lives alone

  • alcohol/drug abuse

  • Lives close

  • Doesn’t stay

  • Employed

  • Up to grade 10 education

  • Single

• Crime Concealment

  • Adult lower class

  • Evening

  • alcohol/drug abuse

  • Lives more than a mile away

  • Single

  • Doesn’t stay at crime scene

  • HS education

• Profit

  • Adult working class

  • Evening

  • Weekdays

  • Lies alone, single

  • alcohol/drug use

  • Doesn’t stay at crime scene

  • Unemployed

  • HS education

Serial Murderers

kill at least 3 people

Visionary Killer

• Hear voices to kill (Devil, demon, or God) - proof of insanity

• No staging of a crime scene

• Harvey Carignan

Comfort Killer

• Kills for profit (insurance, assassination fee, etc.)

• Kills a person of close relationship

• Controlled crime scene

• Many are women

• Judy Buenoano - “Black Widow”

Souvenirs

• A reminder of what happened

• Prevention of victim identification

• Strips victim of identity

• Ex. personal belonging

Trophies

• Has value

• Visual reward serving as an aphrodisiac

• Ex: leg, breast

Crime Scene Elements of Satanic Cults

• Circle of salt

• Candles

• Mockery of Christian symbols

• Satanic symbols

• Blood

• Animal (goat or other hoofed animal)

Situational Child Molester Subtypes

• Regressed Child Molestor

  • Uses children for sex occasionally

  • Coerces kids

  • May have child porn

  • Will have normal adult relationships

  • Uses children when stressed

  • Geographically stable, married, and employed

  • Some alcohol abuse and have low self esteem

  • Jesse and Arnold Friedman - Long Island Piano Teacher (1987-1988)

• Morally Indiscriminate Child Molester

  • Abuses all persons

  • A user

  • Lures, forces, and manipulates

  • Experiments sexually

  • “Into” everything and everyone

• Sexually Indiscriminate Child Molester

  • Likes to experiment sexually

  • Otherwise “normal” person

  • Motivated by kids out of boredom

  • View kids as new and different

  • Highly likely to have kiddy porn

  • Works with kids in some fashion

• The Naive or Inadequate Molester

  • Mental disorder (don’t know right from wrong)

  • “Strange or bizarre” reputation

  • Loners

  • Fondles but doesn’t have sex with kids

  • Nonthreatening

  • Porn, but not kiddy