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Intro to Forensic ScienceForensic Science the application of science to matters of
lawCriminalistics the science responsible for asking the questions
below about any physical evidence found at a crime scene:Recognizing – what is it? Identifying – is it part of the crime scene? Individualizing – what is unique about it?Evaluating – can we use it to solve the crime?
Characteristics of Evidence
Identification The grouping or classifying of
a specific object Class characteristics are used to compare a
piece of evidence and classify or identify it Examples
make and model of a car tire
(Goodyear Wrangler GS-A’s) the caliber of a bullet (.45
cal, 9mm, etc.)
Characteristics of EvidenceIndividualization Discovery of the uniqueness of a given piece of
evidence Individualizing criteria:
NO two things ever happen the same way• The damage to two cars will always be different
NO two things are ever made the same way• Ever try buying white bathroom tile from two different
stores? NO two things ever wear the same way
• Check the bottoms of your shoes for nicks, scratches NO two things ever break the same way
• Give every student in a class a beer bottle, and have them hit each other!
Types of Evidence
Physical evidence objects found at a crime scene
Personal evidence Witness statements subjective - can change – people lie!
Example of personal evidence You are now witnesses at crime scene You must describe the suspected criminal Give his age, weight, and height Describe as many additional features as possible
Suspect Stats6’6+ 340+ 65+
6’5” 320 60-64
6’4” 300 55-59
6’3” 280 50-54
6’2” 260 45-49
6’1” 240 40-44
6’ 220 35-39
5’11” 200 30-34
5’10” 180 25-29
5’9”- 180> 25>
Question: do we really have a crime?
Scenario you walk into an alleywayA red substance covers a dumpster in the
back of a local storeBones are found on the ground near the
dumpster covered in bloodIs there a crime???
Question: do we really have a crime?
“Corpus delecti”the body of evidence (includes both of the
abovethe materials that actually make up the
crime scenephysical evidence and possibly also
personal evidence
Early History Forensics
BabyloniansEarliest use of
thumbprints in business transactions“I will leave my thumbprint on this clay
check, and give you 4 ducks and a goose”
Early History Forensics 44 BC - Julius Caesar stabbed
to death in Roman senate by senators and friends, including Brutus
Case Study #1 – the first autopsyAutopsy - a post mortem exam of a body
• A physician autopsied Caesar, and found only 1 of the 23 stab wounds actually caused his death
What charges are at hand here?Significance of case – it was the first use of
an autopsy to determine cause of death and responsibility
First coroners900 ADone of the oldest
appointed public offices
Coroner - someone who takes possession of a dead person
In modern timescoroner could be
medical examiner or local mortician
1200 AD, Sung Tz’u, Chinese medical
practioner“Hsi Duan Yu” or
“A Washing Away of Wrongs”
first true forensics book Was written to help
medical people determine cases of unnatural death
Case Study #2 – The Bloody Sickle In The Washing Away of Wrongs, the first documented
forensic entomology case is reported. In 1235 A.D., a stabbing occurred in a Chinese village. By testing different blades on an animal carcass, it was
determined that the wound was caused by a sickle. After further questioning, the investigator had all the
villagers bring their sickles and lay them out before the crowd.
Blow flies were attracted to a single sickle because invisible remnants of blood and tissue still adhered to it.
The owner of the alleged sickle later broke down and confessed the crime.
Significance of case – forensic entomology (the study of insects) solved the case
Forensics Becomes a Science
Mathieu Orfilamid 1800’sfather of toxicology Toxicology – the study of poisonswrote “Toxicologie Generale”
• a text on identifying and testing poisons and their use
• showed important applications of chemistry to police investigations
Case Study #3 –
Madame Lafarge Murder Case
Who was Madame Lafarge? young and beautiful widowhusband Charles receives cake
in December while on business trip
Becomes deathly ill but recovers before returning home
Gets better – comes home and dies in January of arsenic poisoning
Madame Lafarge accused of MURDER!bought arsenic at local
pharmacy in NOVEMBERWhy was arsenic available
at pharmacy (like your local CVS)? Significance of Case - First use of expert
witnessesMathieu Orfila – for the prosecutionFrancois Raspail – for the defense But falls off horse, never testifies!
Madame Lafarge found guilty, serves 20 years
Flu shots available!
Rat Poison on Sale!
Alphonse Bertillon (late 1800’s)developed a method of individualization for
criminals and suspects• involved measuring various body parts (side of
skull, length of femur, height, height while sitting…)
Process called bertillonage or anthropometry
worked well until the case of the two Will Wests
Sir Francis Galton Charles Darwin’s cousin wrote equally famous book:
Fingerprints first definitive study of fingerprints
as form of identification Dr. Henry Faulds
Researcher in JapanFascinated with fingerprintsFound scientifically that
fingerprints were quite dissimilarPublished his finding in the 1800’s
in the science journal Nature
1887 - the creation of Sherlock HolmesSir Arthur Conan DoyleEnglish writeraffected the world of forensics
as much as the forensic scientists
Portrayed Holmes as a “scientific detective” who used deductive reasoning to solve crimes
Deductive reasoning: is the process of reasoning from one or more general statements (premises) to reach a logically certain conclusion
Similar to proof writing in geometry!Example – Red Headed League 4:40
Initially – even with a smoking gun in hand
witness statements were taken over physical evidence
Hans Gross - magistratefirst to actually use the scientific method
model of investigationphysical evidence was more important than
personal evidence (witness statements) Criminalistics
Forensic science coined his termThe use of science to study the physical
evidence
Crimes – the Misdemeanor Defined as a “lesser” criminal act Punishment could be any of the
following:Usually a monetary fine;ProbationCommunity service Part-time imprisonment served on the
weekends Incarceration of up to one year in the
local jail
Examples of misdemeanors: disorderly conduct public intoxication DUI petty theft or larceny (under $1,000) vandalism trespassing prostitution drug possession
Crimes – the Felony
DefinitionA crime which involves a
potential punishment of one year or longer in prison
Felonies can be categorized as either violent or non-violent (property and drug)
Felons – persons committing a felony crimeTypically incarcerated in a prison, not a local
jail
Felony include, but are not limited to: burglary robbery assault battery illegal drug use/sales grand theft or larceny(over $1,000) arson rape murder
Crimes of Theft Larceny – the wrongful withholding of
another’s property Examples:
Shoplifting - removing items from a business while not employed by the business
Loan sharking - lending money at higher than normal rates (shylocking)
Auto theft – think GTAFraud - a deception deliberately practiced in order
to secure unfair or unlawful gain (shady builders)Embezzlement - theft of monies from an
organization
Crimes of Theft Burglary
breaking into a dwelling at night with the intent to commit a felony
Breaking and enteringBreaking – to enter a premises without
permissionEntering –to place either oneself or a tool inside
Robbery the wrongful withholding or theft of another’s
property while in their presenceExamples: mugging, carjacking
$%&@
Other Crimes of Property Forgery
the process of making or imitating objects, statistics, or documents
with the intent to deceiveExamples: wills, checks, valuable items
Identity theftAdapting some else’s individual information
and presenting as your own Info that allows for identity theftSocial Security #, address, stolen PIN #s,
credit card info from a skimmer
Crimes of Violence Assault
threat or use of force on another that reasonably makes that person fear bodily harm
Battery the use of force on another resulting in harmful contact (injury)
Aggravated assaultmade worse by more serious circumstances, such
as • deadly force• violence• or the commission of another crime
Crimes of Violence Rape
unlawful sexual intercourse with a person without their consent
An act of violence, not just sex Date rape
often involves drugs to render victim unconscious
Statutory rapehaving sex, with or without consentwith an underage minoror a person of limited mental abilities
Crimes of Violence
Arson – defined as the ignition or lighting on fire of a dwelling with malicious intent
Reasons for arsonMonetary gainVengenceAngerThrill seeking Serial arsonists
Crimes of ViolenceHomicide
the killing of one person by anotherCriminal homicide
the felonious and wrongful act of killingTwo forms
• Manslaughter - the wrongful killing of another without premeditation– Ex: drunk driver kills someone
• Murder - the wrongful killing of another with premeditated intent– Ex: drug store shooting in Medford
First Degree Murder:an intentional killing that is willful, deliberate and
premeditated• You wait in the parking lot and shoot Mr. Foley
as he gets out of his car Second Degree Murder
homicide committed by an individual as a principal or an accomplice while perpetrating a felony • You and a friend rob Mr. Foley, and your friend
bludgeons him to death Third Degree Murder
Any other murder, where the intent was not to kill, but to harm the victim• You push Mr. Foley down a stair and he dies
Innocent homicide the death of another without intent
to do harm, or lacking felonious intent.
Two types of innocent homicideExcusable homicide - homicide occurs, but is
not felonious and intent is not evident• accidental death• self defense
Justifiable homicide - an authority says homicide is legal• War• Police actions• State execution