FORS-2106EL Lecture Notes - Lecture 3: Jean Derome, Image Analysis, Morphine
27 Jun 2018
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Forensics Biology - Day 3 2017.09.14.
Brief History of Forensic Science
What is forensic science?
-a process applied to the law
-science: theory, explanation, test it to see if it is valid, is a process
-therefore we will test different possibilities/scenarios in cases/scenes
-ex. broken window, shards on outside or inside of house? this can tell you about
the direction of where the force was, a fight that broke it? someone trying to set
the crime scene by pretending it was a breakaway sight, but broke it from the
inside
-focusing on one single object in a case causes investigative bias
-taking evidence and trying to fit it into a scenario is a inductive evidence
-in forensic science they don’t like using the word “match”, because (in terms of DNA)
this would mean that it would match every single base pair, which it didn’t
-prefer to say “ we failed to exclude this person’s DNA”
-they will say “ we tried to eliminate this person (defendant) from the possibility” and
use stats to show how likely it is him
-this is to try to reverse the bias
-we draw upon a lot of different sciences
-forensics comes from the latin word “forum” which comes from ancient rome where
you actually brought someone to the forum when you have a case towards someone,
but then others hired people to speak for them and this was the start of lawyers
-forensic science must be unbiased
-we provide evidence that can support or refute evidence from the investigators
What are its limits?
-can you always tell who the perpetuator was?
-ex. touch DNA, where they use only swabs of DNA from firearms and other objects
to try to accuse someone, but this is not very accurate
-forensic science has limits, the tests we use to come to the determinations do have
limits since it is humans that have to write up these reports, and tell these reports to
the court which means that there will always be human errors that can occur
Forensic Science Defined
-Application of science of the law
-Civil and Criminal law
-Forensics can be used in both, but mainly criminal law
-Criminal Law
-Ever changing
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-ex. marijuana consumption
-Science provides information to law enforcement concerning the events
surrounding a crime
-Saferstein (2015:4)
-“Forensic science…is the application of science to the law…applies the knowledge
and technology of the definition and enforcement of such laws.”
Development of Forensics
-Need to identify and compare physical evidence
-someone can lie about who they are, and identification is important to prosecute
the correct individual
-this is done through fingerprints and DNA now
-for physical evidence, you need this to ensure what you are looking at is what you
say it is using different tests
-ex. blood vs horseradish
-Born out of necessity
-Sir Arthur Conan Doyle
-Creator of Sherlocke Holmes
-Police officers and general public became obsessed with using evidence to solve
cases
-Edmond Locard
-1977-1966
-Locard’s Exchange Principle
-Cross-Transfer of evidence
-One of the “hallmarks” of linking suspects to crimes/victims/location
-ex. putting hands on table, you leave DNA and skin cells, you take dust particles
and other particles
-A. Bertillion
-Berlin Measurements for Identification: using measurements of the a persons body,
of things that don’t change and fluctuate throughout their life
-this is called anthropometry, the measuring of people
-ex. measurement from nose to start of eye distance
-CCTV identification
-close circuit television identification
-it is difficult to actually properly identify someone from this
-when tested, half the tests of the people actually were wrong
-but this does offer an investigative lead to start up on
-Wilkinson and Evans, 2009
-Study that asked: Are facial image analysis experts any better then the public at
identifying individuals from CCTV image?
-Experts are consistently better at identification from these images then the public
-Double the identification rates with half the errors
-Training and experience in facial analysis will produce more reliable and accurate
results
find more resources at oneclass.com
find more resources at oneclass.com
