Introduction to Forensics - Tri-City

Download Report

Transcript Introduction to Forensics - Tri-City

Course Outline
 Topics to be covered








Ch 1: Introduction to Forensics
Ch 2: The Crime Scene
Ch. 9: DNA Evidence
Ch. 17: Document Examination
Ch. 15: Fingerprinting
Ch. 16: Firearms, Toolmarks, and Impressions
Ch. 10: Bloodstain Pattern Analysis
Ch. 4: Drugs
Course Requirements
 Reading…a lot of reading
 Vocabulary
 In-class Labs
 Online CSI Labs
 Netflix Cases: Summarization Writings
 Review Questions
Ch 1: Introduction to
Forensics
 Key Terms




Forensics
Expert witness
Locard’s exchange principle
Scientific method…..yes, even in forensics
Objectives
 Familiarize yourself with the various fields of
forensics
 Investigate the history of forensics and scientific
advances in forensics
 Examine possible career fields in forensics
 Understand the role of the forensic scientist in the
criminal case.
Def. and Scope of Forensic
Science
Forensic Science is an
umbrella term that covers
a variety of professions
Forensic Science is the
application of science to
the criminal and civil
laws that are enforced by
police agencies in a
criminal justice system

11 Sections of Forensic Science

Criminalistics

Digital and Multimedia
Sciences

Engineering Science

General

Jurisprudence

Odontology

Pathology/Biology

Physical Anthropology

Psychiatry/Behavioral
Sciences

Questioned Documents

Toxicology
TV vs Real-life Forensics
 Shows like CSI and NCIS have increased the
publics knowledge on Forensic Science, but has
also skewed expectations of most when it comes to
entering the field of Forensics.
 In shows, one person or a small group will collect
evidence, analyze, interrogate, and testify.
 In the real world, these duties are very
departmentalized and carried out by several
people in different branches.
TV vs. Real-World Forensics
 On TV: Every crime scene yields tons of crucial
physical evidence and the CSI’s are solely
responsible for solving crimes.
 However, most cases do not produce much
evidence and it cannot be expected that this type
of evidence is needed for a conviction
Some jurors have come believe that the prosecution
must have forensic evidence for a conviction.
This detracts from the real goal of forensics: The Search
for the Truth…….Can you handle the Truth about
Forensics?
History and Development of
Forensic Science
 No one origin; history has several instances of
individuals using close observation of evidence
and applying basic scientific principles to solve
crimes.
 Initially forensics was less careful and systematic.
Think Sherlock Holmes here, not Abby Scuito
 Modern Forensics combines tools and skills from a
variety of disciplines and merges them together in
the search for truth.
Early Developments
 Yi Yu Ji (A Collection of Criminal Cases) from 3rd
century China
Murder case: Wife killed husband and burned house
down around him
Coroner used 2 pigs experiment to prove her guilt
Burnt one pig alive and the other dead
Examined the mouth of each pig for ashes
Chinese first to recognize fingerprints were a way to
possibly ID a person.
 Careful examination like this was not normal for
forensic examination of the time
Early Developments
 Lack of knowledge about anatomy and pathology
limited forensics until the late 17th century.
 1st notes on fingerprint characteristics: 1686 by
Marcello Magpighi (Italian professor)
 Did not cite any evidence as far as using
fingerprints as a means of identification.
 1st paper on this did not appear for over 100 years
Initial Scientific Advances

Advance is both anatomy and chemistry in the 18th Century led to
greater advances in forensics as well.
 1775 – Carl Wilhelm Scheele devises first test for detecting
arsenic
 1798 – Francois-Emmanuel Fodere writes “Treatise on Forensic
Medicine and Public Health.
 1806 – Valentin Ross furthers Scheele and develops test for
detecting traces of arsenic in the stomach lining
 1814 –Mathieu Orfila, the father of toxicology, publishes articles
on the detection of poisons and their effects of animals
 1828 – William Nichol invents polarizing microscope
 1839 – first testimony on toxicology by James Marsh
 1839 - Bayard formulates procedures for detection of bodily fluids
 1853 – microcrystalline test for hemoglobin
 1863 – first test to detect blood
 1850s and 1860s – photography helps document evidence
Late
th
19
Century Progress
 By late 1800’s, knowledge from all fields of science was
being used to study crimes.
 1879 – Alphonse Bertillon develops first system of
identification (anthropology and morphology info) by taking
a series of body measurements to distinguish individuals
from each other
 He called his system “anthropometry”
 Using for nearly 2 decades, but has since been replaced
by fingerprints
Fingerprinting became common practice in the early 1900s
Late
th
19
Century Progress
 Thomas Taylor – suggests fingerprints could be
used as means of identification
 Henry Faulds makes same suggestion 3 years later
 Henry Galton – 1st definitive study of fingerprints
as a means of identification.
 Published book “Finger Prints” in 1892 that proved
this to be true
Late
th
19
Century Progress
 1893 – Hans Gross writes first comprehensive book
describing applications of science to the field of
criminal investigation.
Gross was an Austrian prosecutor and judge.
Published book “Criminal Investigation” that
detailed ways to use things like microscopy,
chemistry, physic, etc to aid in a criminal
investigation
Late
th
19
Century
 Most famous figure in 19th Century Forensic
Science: Sherlock Holmes…..no he was not real!!!
 Created by Sir Arthur Conan Doyle
 Popularized scientific crime-detection methods
 First published novel in 1887
th
20
Century Breakthroughs
 The sciences went into hyper-speed as far as
advancements go.
 1901 – Karl Landsteiner discovers blood types
 1915 – Italian professor Leone Lattes creates test to
identify blood type from dried stains.
 1910’s – Albert S. Osborn conducts
groundbreaking work on document examination
and published Questioned Documents, which is still
used for reference today.
th
20
Century: Locard
 Edmond Locard – early 1900’s
 Applied scientific method to forensics and created
a workable crime lab in the attic of Lyons PD.
 He became world famous and founded/directed
the Institute of Criminalistics at Univ. of Lyons
 Locard exchange principle – when two objects
come into contact with one another, there is
exchange of materials between them.
th
20
Century: Microscopy
 Microscope became widely used in 20th Century
forensics.
 Dr. Walter C. McCrone – world’s preeminent
microscopist – leading figure
Leading instructor of microscopy applied to
forensics.
Taught techniques and analysis of evidence
 Col. Calvin Goddard
Comparison microscope – firearms examination
Comp. microscope still used to this day
Assignment
 Read Chapter 1, pages 3-10
 Do Review Questions 11-15
 Due next class
Modern Scientific Advances
 Mid- 20th Century: The Computer!!!!!
 The computer has allowed for huge advances in
the field of forensics, as well as all other sciences.
 Advanced techniques for analyzing evidence were
created.
They were easier to perform, faster, and more
accurante than earlier tests.
Ex: chromatography, spectrophotometry, and gel
electrophoresis…..we cover these later.
Modern Advances - DNA
 The most important advancement was the
discovery of DNA and sequencing of DNA in the
late 20th Century and early 21st Century.
 DNA profiling – developed by Sir Alec Jeffreys in
1984.
It was first used in 1986 (that’s the year I was born) to
solve a murder of two young English girls.
This also was the first time DNA typing was used to
prove innocence in a case.
DNA is arguably the most powerful tool in forensics. It
can prove guilt to an accuracy of 99.9%
Modern Advances - Databases
 Creation of computerized databases has allowed
physical evidence to be shared worldwide
 Databases for fingerprints, DNA, firearms
markings, and spent shell casings are now in use.
 This has made evidence analysis easier:
Scan the evidence into the database
Search for a match
This can narrow down lists of suspects quickly
The Modern Crime Lab
 Services:
Physical science unit
Biology unit
Firearms unit
Document examination unit
Photography unit
Toxicology
Latent fingerprints
Polygraph
Voiceprint analysis
CSI unit
Crime Lab Services
 Physical Science
 Apply chemistry,
physics, and geology
 Examine glass,
chemicals, paints,
explosives, soil
 Perform

Drug ID
 Soil/Mineral Analysis
 Biology
 Biology and
biochemistry
 Perform

DNA profiling

Blood typing

Hair/Fiber analysis

Bodily fluids
 Wood/plant material
analysis
Crime Lab Services
 Firearms unit
 Examine firearms,
discharged bullets,
spend shell casings,
ammunition, etc
 GSR analysis
 Comparison
microscope – used to
do side-by-side
analysis of bullets
 Document Examination
 Examine handwriting
and typewriting
 Determine source
and/or authenticity
 Ink/paper analysis
 Indentions, erasures,
obliterations, and
burned and charred
documents
Crime Lab Services
 Photography
 Take crime scene
photos to document
physical evidence
 Digital imaging,
Infrared, UV, X-ray
photography as well
 Prepares photographic
exhibits for courtroom
presentations
 Toxicology
 Sub-unit of biology
 Examine bodily fluids
and organs for the
presence or absence
of drugs or poisons.
 Often work in
collaboration with
coroner.
 Some toxicology done
in the field: intoxilzyer
– presence of alcohol
Crime Lab Services
 Latent Fingerprints
 Collect fingerprints
 Scan them into IAFIS –
Integrated Automated
Fingerprint
Identification System
 Polygraph
 Administer “Lie
detector tests”
 More a tool of the
criminal investigator
than the forensic
scientist but early on
was also used by crime
labs.
Crime Lab Services

Voiceprint Analysis

Crime-scene Investigation
 Identify/match telephone
voices to people.

Evidence Collection at
the Crime Scene.
 Used in threats and taperecorded messages.

Collect Evidence
 Use tool called sound
spectrograph to create a
visual graph of people’s
voices.

Based off the premise
each person’s speech
pattern is unique to the
person
 Preserve/Bag/Label
Physical Evidence that
will later be examined in
the crime lab.
Other Services

Forensic psychiatry



Determining if defendant is mentally fit to stand trial
Evaluate psychological disorders
Profiling
 Forensic odontology



Forensic engineering



Dental evidence – reconstruction, identification
Bite mark analysis
Accident reconstruction, failure analysis, origins of fire/explosions
Determine if something was an accident or a crime
Forensic computer/digital analysis

“hackers” – analysis/obtain evidence from computers and media
devices
Assignment
 Read pg. 11-15
 Review Questions 17-19, 25-27
 Anyone who has not gotten their video form signed
you need to do so; we start “NOVA: Forensics on
Trial” tomorrow