Forensic Science

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Intro to forensic science

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Define “Forensic Science”
Explain the limits of forensic science
Describe Locard’s Exchange Principle
1
Identify the types of forensic work
Differentiate Reconstruction & Re-enactment
4
3
1
2
Learning Objectives
5
2
3
Diverse subject
A forensic scientist cannot tackle all subjects
Specialists
Fingerprinting
Physical
evidence
Forensic
Medicine
Forensic
Science
The body
Documents
Ballistics
Drugs
DNA
4
Forensic Medicine vs Forensic Science
M.D.
BS / BSc.
Living Dead
Chao Tze
Cheng
Pornthip
Rojanasunan
Sir Bernard
Spilsbury
5
Forensic Scientist = Celebrity?
6
Murder Rates Worldwide
Per 100 000 population (reported)
7
Murder Rates Worldwide
Honduras
71
U.S.A.
4.7
Washington D.C.
23.8
Singapore
0.51
U.K. 1.23
Colombia
33
1
What is Forensic Science?
How did they know?
Based upon forensic science
Scientific principles
"Strong evidence”
2
What is Forensic Science?
Evidence
Interpretation
3
What is Forensic Science?
Interpretation of evidence
Found at crime scene
1
Physical objects or measurements
4
What is Forensic Science?
Evidence
Interpretation
Reliability
5
What is Forensic Science?
Reliability of evidence
How evidence can be trusted
2
To what extent it can be trusted
DNA very reliable
6
What is Forensic Science?
Cannot be
deduced
Evidence
Interpretation
Reliability
Can be
deduced
7
What is Forensic Science?
Can / cannot be deduced from evidence
3
Some aspects beyond the
power of forensic science
Limits of forensic science
8
Why Science?
Philosophy of all science
Newton
Observations
Natural world /
crime scene
Experiments
9
Why Science?
Observations
& Experiments
Theory
Issac Newton
10
Scientists
Scientific paper
Presentation at
a conference
Theory
11
Forensic scientists
Present theory in court
Convince judge / jury
Theory
Expert Witness
Send an innocent
person to prison / death
Wrong theory
12
Procedures in a case
Evidence from:
Experts,
Witnesses,
Police
Prosecution
v.s. Defense
Verdict
13
Verdict given by
Judge
Judges
14
Jury
Local citizens
Abolished in
some countries
Verdict given by
Jury
Judge
15
Presumption of Innocence
Innocent until proven guilty
Defense does not have to prove innocence
Prosecution has to prove guilt
Reasonable doubt
16
Presumption of Innocence
Innocent until proven guilty
beyond reasonable doubt
17
18
September 2009
Randone called the emergency services
Felica Lee found dead
Sent for autopsy
19
Autopsy results
Over 300 “blunt force trauma wounds”
Randone charged
Murder
Torture
20
Prosecution
1
Torture: Kicked
by Randone
Cause of death:
Asphyxia by
smothering
Trial
1
2
21
Autopsy results
Blood chemistry
Felicia Lee’s blood contained
gamma-hydroxybutarate (GHB)
22
Prosecution
Defense
Verdict
1
2 3
Torture: Kicked
by Randone
Expert witness
Not
guilty
Cause of death:
Asphyxia by
smothering
Trial
1
2
Cause of death:
Seizure caused
by GHB
1
23
Verdict
Did defense prove Lee’s death
was caused by a drug overdose?
No
Suggested a reasonable possibility
1
need to convince court of the validity of
scientific evidence especially since jury
generally not have any scientific training
themselves
2
Bournemouth, England, 1939
Walter Dinivan
Skull crushed
Died without
regaining
consciousness
Wealthy
64 year old found
unconscious at
home
3
Problem
Only one witness
Had to rely on forensic evidence
Dead
victim
4
Safe and
pockets
emptied
Crumpled
up brown
paper bag
Cigarette
butts on
the floor
1
2
3
Police found
Robbery Held murder
weapon?
Friends?
so that wont leave any fingerprints
conversation
escalated into a
fight which then
lead to murder
5
Investigation
Joseph
Williams
Came into
money
Suspect
Poor
From Walter
Dinivan?
6
Few years ago
Discovery
Use saliva to determine blood type
True for most of the population
7
Using new technology
Cigarette
butts
Test the
blood group
Blood type AB
Saliva
Rare
8
Joseph
Williams
Came into
money
Suspect
Poor
From Walter
Dinivan?
Blood
group?
Investigation
9
Joseph Williams
Police followed him into a pub
Bought him beer Gave him cigarettes
Collected glasses & cigarette ends
Analyzed blood group
Extracted saliva
10
Joseph
Williams
Came into
money
Suspect
Poor
From Walter
Dinivan?
Blood
group?
AB
Investigation
11
Police presented evidence
Motive
Joseph Williams arrested,
charged and taken to court
Investigation
Reasonable evidence
12
Defense
Verdict
Saliva
Jury persuaded to disbelieve forensic evidence
Cannot be used to
determine blood group
Not guilty
13
After the trial
Williams went
celebrating
Drunk
Confessed
to a journalist
Published story after
Williams’ death
14
15
Singapore, 1996
Madam Singh
Murdered
Cigarette butts
Evidence
Stabbed in the neck
No technology Evidence stored away
16
Singapore, 2005
DNA
extracted
Evidence
presented
Saliva
extracted
Cigarette
butts
Zulkarnian
Kemat
Verdict:
Guilty
1
Court case
Have to show
Criminal action was committed
Intention to commit the criminal action
1
2
2
Limits of Forensic Science
Actus Reus Mens Rea
A guilty mind
or intention
1
A guilty action
Evidence from
crime scene
1
2
In someone’s head
2
3
Dick Cheney Frank Whittington
4
Quail hunting trip
Dick Cheney fired at quail
In Texas
Shot Frank Whittington by accident
5
Footprints in the ground
Forensic Science
Fingerprints on the gun
Pellet from Frank Whittington
Could have shown that Dick
Cheney shot Frank Whittington
6
Why did Dick Cheney do it?
Motive?
Accident?
Forensic Science
7
Physical evidence only
shows Actus Reus
8
Tells you about
Does not tell you about
Forensic Science
Mens Rea
Actus Reus
“Actus non facit reum nisi mens sit rea”
The act does not make a person
guilty unless the mind is also guilty
9
Application of science to
Law
Criminal justice
What is Forensics?
Lady Justice
10
Physical
What is Forensics?
Analysis of evidence
Chemical
Biological
Lady Justice
11
Forensic Science can...
Reconstruct past sequence of events
12
Forensic Science can...
Forensic
evidence
Fibres
Hair
Blood
Broken glass
Fibres
Paint flakes
Fingerprints
Shoeprints
13
Forensic Science can...
Link a suspect to a crime scene
Reconstruct past sequence of events
14
Deciding the charge
Koh Kailin
Had a baby
Dumped the baby
Baby found
Mother was traced
and investigated
15
Deciding the charge
Dead baby
Murder charge reduced to a less serious charge
Murder?
Very premature baby Pathologist
Stillborn?
Suicide?
16
Bukit Merah, Singapore, 1972
Boy run over by a train
Accident?
Forensic medicine specialist
Inconsistent injuries
Bukit Merah
train tracks
Pressurized arteries
17
Blood spatter
Living body
Blood will spurt out in
considerable quantities
Severed artery
Arteries not pressurized Dead body
Lesser blood will spurt out
18
Blood spatter
Too little blood at the scene for a living body
Police investigation
Boy was murdered
Made to look like a suicide or accident
Murderer caught and convicted
1
Uses of Forensic Science
Art
2
Uses of Forensic Science
William Shakespeare?
Shakespeare
(1564 – 1616)
1818 paint
Art
3
Uses of Forensic Science
Reconstruct past events
Drug tests
Archaeology
Sport
International politics
Art
4
Uses of Forensic Science
Bosnian conflict Bosnian conflict
International politics
Archaeology
Sport
Art
5
Uses of Forensic Science
Disasters 2004 tsunami
International politics
Archaeology
Sport
Art
6
Forensic Science
Being done in fiction books
before being done in reality
About 100 years old
7
Fictional character
created by Sir Arthur
Conan-Doyle
8
Sir Arthur Conan-Doyle
Arthur Conan-Doyle
Eye doctor
Wrote stories
to pass time
9
Edmond Locard
(1877 – 1966)
Locard’s Exchange Principle
10
“Wherever he steps, whatever he touches, whatever he leaves,
even unconsciously, will serve as a silent witness against him. Not
only his fingerprints or his footprints, but his hair, the fibers from his
clothes, the glass he breaks, the tool mark he leaves, the paint he
scratches, the blood or semen he deposits or collects. All of these
and more, bear mute witness against him. This is evidence that
does not forget. It is not confused by the excitement of the
moment. It is not absent because human witnesses are. It is
factual evidence. Physical evidence cannot be wrong, it cannot
perjure itself, it cannot be wholly absent. Only human failure
to find it, study and understand it, can diminish its value.”
Professor Edmond Locard (1877-1966)
Locard’s Exchange Principle
11
“Wherever he steps, whatever he touches, whatever he leaves,
even unconsciously, will serve as a silent witness against him. Not
only his fingerprints or his footprints, but his hair, the fibers from his
clothes, the glass he breaks, the tool mark he leaves, the paint he
scratches, the blood or semen he deposits or collects. All of these
and more, bear mute witness against him. This is evidence that
does not forget. It is not confused by the excitement of the
moment. It is not absent because human witnesses are. It is
factual evidence. Physical evidence cannot be wrong, it cannot
perjure itself, it cannot be wholly absent. Only human failure
to find it, study and understand it, can diminish its value.”
Professor Edmond Locard (1877-1966)
12
“Every contact leaves a trace”
Edmond Locard (1877 – 1966)
Locard’s Exchange Principle
13
“Wherever he steps, whatever he touches, whatever he leaves,
even unconsciously, will serve as a silent witness against him. Not
only his fingerprints or his footprints, but his hair, the fibers from his
clothes, the glass he breaks, the tool mark he leaves, the paint he
scratches, the blood or semen he deposits or collects. All of these
and more, bear mute witness against him. This is evidence that
does not forget. It is not confused by the excitement of the
moment. It is not absent because human witnesses are. It is
factual evidence. Physical evidence cannot be wrong, it cannot
perjure itself, it cannot be wholly absent. Only human failure
to find it, study and understand it, can diminish its value.”
Professor Edmond Locard (1877-1966)
14
Obvious traces
False teeth
Some traces are more
obvious than others
London, 2007
A burglar left his
false teeth behind
15
More than one way
to leave fingerprints
behind…
16
Obvious traces
Elliott’s Builders Merchants
17
Obvious traces
Diesel in
backyard
Stolen
Severed
finger found
Hospitals
contacted
Culprit was
arrested &
convicted
Attached razor wire
to the back wall
1
2
Murder or suicide?
Banco
Ambrosiano
“God’s banker”
U.S. $1.2
billion missing
Roberto Calvi
3
Murder or suicide?
11 June
Disappeared
from Milan
19 June
Hanged under
Blackfriars Bridge
Roberto Calvi
4
Blackfriars Bridge
5
Roberto Calvi
Shaved his moustache
Escaped to London
Adopted a false name
Got a false passport
6
Police
Roberto Calvi
Unable to escape
Unable to answer for the missing money
Committed suicide
7
Roberto Calvi’s Son
Was convinced that Roberto
Calvi did not commit suicide
Suicide
Second inquest
Inquest
8
Bricks in suit pocket
False passport
U.S. $14 000 in wallet
Bags packed
1
2
3
4
Police
For drowning
Opportunity to travel
Going to travel?
9
Neck not broken
No drugs in blood
No signs of a struggle
No water in lungs
Watch stopped at 1:52 am
1
2
3
4
5
Pathology
Time of hanging
Not drowned
10
Murder or suicide?
Climbing up and down the scaffolding
Blackfriars Bridge under maintenance
Surrounded by yellow painted scaffolding
Get yellow paint flakes and
rust marks on clothes or body
11
No paint flakes
Roberto Calvi did not climb down
No rust marks
May have been raised up to scaffolding
1
2
Forensics
12
Questions
Why a rope and bricks?
Where did he get the rope?
Why no paint flakes on him?
Why choose a cold river and not the hotel?
How did he travel from hotel to bridge?
1
2
3
4
5
13
14
Not a suicide
Likely to have been murdered
Questions
Not sufficient evidence to convict anyone
Who killed Roberto Calvi?
1
2
Moffat, Scotland, 1935
Packages found in river
Numerous body parts
wrapped in newspaper
Moffat
3
Questions
How many bodies?
Who were they?
1
2
Newspaper wrappings
Two female bodies
4
Morecomb
e
Special edition
of Morecombe
newspaper
Answers
Police contacted
“Mrs.” Ruxton
& her maid
Moffat
5
Skeletal remains
Flesh and distinguishing
features removed
How to identify the body?
Face
mutilated
Fingers
removed
6
Identifying the bodies
Photographs of the women
Look at the angles the women posed in
7
Identifying the bodies
Bodies proved to be
Mrs. Ruxton & her maid
Buck Ruxton arrested
Superimposed
the two photos
8
Other evidence
Bloodstains in the
Ruxton house
Ruxton claimed innocence
Convicted of murder
Jury did not believe claim
Buck Ruxton
9
Other evidence
Controversial case
Photographs not good
enough as evidence?
Buck Ruxton confessed
Validated technique Buck Ruxton
Around the World
1
1910 Lyon, France
1915 Germany
1923 Austria
U.S.A. (L.A.P.D.)
Set up by Edmond Locard
Around the World
2
1932 U.S.A. (F.B.I.)
1935 U.K. (Scotland Yard)
1925 Holland
Finland
Sweden
Now all part of the Health Sciences Authority
In Singapore
3
1960s
Pathology lab Chao Tze Cheng
1929 Chemical analysis service
Straits Settlements Police
Firearms Unit
Photography Unit
Toxicology
Latent Prints
Polygraph Voiceprint
Psychiatric profiling
Computer
& Electronic
Forensics
Forensic Entomology
Forensic Engineering Forensic Geology
Forensic Anthropology
Facial Reconstruction
Forensic Odontology
4
Documents Unit
DNA Lab
Physical Science Unit
Biology Unit
Forensic Science Laboratories
Physical Science Unit
5
Biology Unit
Chemical and physical analysis
Chemical tests, spectroscopy, microscopy,
drugs, material fragments, explosives
Biological samples
Hair, plants
DNA Lab
6
Firearms Unit
Essential
Guns, bullets, cartridge cases, firearm damage
DNA analysis services
Documents Unit
7
Photography Unit
Determine faked or forged documents
Analysis of handwriting, prints, paper, ink
Recording & presenting of evidence
Determine real & fake photographs
8
Photography Unit
9
Discontinuous
black line
Pixels are
mis-matched
Different angle
of shadows
1
2
3
Not genuine?
Photography Unit
10
“Surgeon’s” photograph
Loch Ness Monster?
Genuine photo
Model monster
Loch Ness Monster?
Toxicology
11
Fingerprinting
Polygraph
Drugs and poisons in body fluids and organs
Visible and latent prints
Can we scientifically detect a lie?
Voiceprint analysis
12
Osama bin Laden
Audio recordings
of his voice?
Proving that a
voice belongs to a
particular person
Voiceprint analysis
Howard
Hughes
13
Clifford Irving claimed to
possess Howard Hughes’
authorised biography
Denied by Hughes
Teleconference
Recordings compared
Irving convicted of fraud
Psychiatric Profiling
14
Computer Forensics
What can we tell about the criminal
from the way they commit the crime?
Retrieving deleted data
Following of electronic trail
Forensic Engineering
15
Minneapolis I-35 bridge collapse
Design fault of bridge
Corrosive effect of pigeon droppings?
Minneapolis
I-35 bridge
Why?
16
Forensic Geology
Forensic Entomology
Using insects to provide information
Soil analysis
Mineral content
17
Forensic Anthropology
Analysis of skeletal remains
Skeletal remains
When people die in remote places
Only found after the body has decomposed
Joseph Schexnider
18
No other evidence
Abbeville, 2011
Human skeleton found
in an old chimney
Identified as Schexnider
Disappeared in 1984
19
Facial Reconstruction
Take skull and rebuild flesh
See how person looked
like when they were alive
Karen Price
20
Facial Reconstruction
Reconstructed
face shown on TV
Victim recognized
immediately
Skeleton found
Alexander Fallon
21
Facial Reconstruction
Difficult to tell age
15 years before
he was identified
Killed in 1987
22
Facial Reconstruction
Used modelling clay
Now done electronically
23
Forensic Odontology
Identification of victim remains
Identification of criminals
Using teeth to provide information
1
2
Ted Bundy
24
Forensic Odontology
Bite mark on victim
Comparison to his
teeth impressions
Convicted & executed
25
J. G. Haigh
26
J. G. Haigh
“Acid Bath Haigh”
Killed 9 people
27
J. G. Haigh
“Acid Bath Haigh”
Killed 9 people
Olive Durand-Deacon
Led to his capture








Olive Durand-
Deacon
Lured Mrs. Durand-Deacon
there with talk of investments
28
No conviction for a
crime without a body?
Had a countryside shed
J. G. Haigh
Misunderstood the concept
29
J. G. Haigh
Must be the body of evidence to
prove the occurrence of a crime
Haigh: “No murder charge
without a real body”
Destroyed victims’ bodies
30
J. G. Haigh
Dissolved them in sulfuric acid
31
Evidence of murder
Gall-stones
False teeth Individualised
1
2








Dental records
1
Identification & Individualisation
Identification
What is it?
1
Looking at it
Chemical or
biological tests








2
Identification & Individualisation
Identification
What is it?
Classification?
1
2
Class characteristics
3
Identification & Individualisation
Identification
E.g. A shoe
What type?
2
What brand?
1
Men’s or
ladies’shoe?
3
4
Identification & Individualisation
Identification
E.g. A fibre
Cotton,
wool, nylon?
What kind of fibre?
E.g. A shoe
1








5
Identification & Individualisation
Identification
What calibre bullet?
2
What kind of bullet?
E.g. A bullet
1
E.g. A fibre
E.g. A shoe
6
Identification & Individualisation
Individualisation
Narrowing class to one
1
Identification
What is it?
Classification?
1
2
7
Identification & Individualisation
E.g. A shoe
Identify whose shoe it is
Not always possible to do so
Identify shoe brand
















8
Identification & Individualisation
Who is the
manufacturer?
1
E.g. Clothing
Individualisation
Fingerprints?
9
Identification & Individualisation
Serial number?
1
2
E.g. Clothing
Individualisation
E.g. Tool
10
Identification & Individualisation
Individualisation
Trace elements
or impurities?
E.g. Of chemical origin
1
E.g. Clothing
E.g. Tool
11
Identification & Individualisation
Individualisation
Blood type?
E.g. Of chemical origin
1
E.g. Tool
E.g. Biological samples
DNA analysis
2
E.g. Clothing
12
Forensic
evidence
Fibres
Hair
Blood
Broken glass
Fibres
Paint
Fingerprints
Shoeprints
Comparison leading to Association
13
Reconstruction Re-enactment
Understanding
past events
Re-do one of
the events
1
2
Part of reconstruction
1
Reconstruction & Re-enactment
14
15
2005 London Bombings
July 7 bombings
4 bombs exploded
on public transport
52 people killed
After the bombing
16
2005 London Bombings
July 21
Abandoned bomb found
Terrorists arrested
Failed repeat bombing
17
2005 London Bombings
Abandoned bomb found
How the bombs
were constructed
What the bombs
were made of
2
1
Detonator
Home made
explosive
18
Bombers
Four attempted to detonate their bombs
One abandoned his bomb
19
Bombers
Numerous forensic and CCTV evidence
Defense
Motive
Cannot claim those people
were not the bombers
Hoax bombs
20
Mens Rea
What was their intention?
Built for hoaxes?
Built to cause destruction?
Use forensic science to determine if bombs were
21
Mens Rea
Reconstructed bomb
Re-enactment of explosion
Intention to cause death and destruction
Not a hoax
22
George Smith
23
George Smith
Marry women
Steal their money
Murder them
1
2
3
24
Smith’s wives
Took a bath
Had an epileptic fit
Drowned
No sign of struggle
or bruising
Died the same way
Bathtub
25
“Brides in the Bath”
Married seven women
Question Drowned accidentally?
Murdered?
Three died
26
“Brides in the Bath”
If murder by drowning
Leaves a lot of bruising
No signs of bruising
Should have a violent struggle
27
Sir Bernard Spilsbury
Re-enactment Female divers
Pull their feet
Heads went underwater
Unconscious
No struggle
28
Gareth Williams
29
Gareth Williams
Cryptographer working
for British Intelligence
Found in his apartment
in August 2010
Dead for 9 days
30
Investigation found
No signs of a struggle
No traces of poisoning
2
1
No sign of asphyxiation
3
In the bath
31
Evidence
Body found
in sports bag
Padlocked on
the outside
2
1
3
81 x 48 cm
Sports bag
32
Gareth Williams
Yoga experts unable to lock and
padlock ownself from the outside
Re-enactment
Question
http://www.youtube.com/watch?v=lkirbdxzkq8
Locked by someone else?
1
Richard Crafts Helle Crafts
2
The Woodchipper Murder
Married
3
The Woodchipper Murder
Married
Guns
Machinery
Travel
2
1
3
Had trouble
with money
Hired P.I.
Helle dropped off at home
4
1986
Nov 19
th

Nov 18
th

Richard sent the children to his sister’s house
Dec 1
st

P.I. contacted
the police
Only Richard answers the phone
5
Police investigation
Richard: “wife disappeared”
Passed a lie
detector test
1
Carpet fragments
Strange purchases
Chainsaw
Freezer
Woodchipper
No blood
2
3
6
Christmas Day 1986
Crafts’ house searched
Bloodstains on mattress
1
Matched Helle’s
blood type (O+)
Witness placed wood-chipper at Lake Zoar
Searched river bank
1
Human hair
Letters
7
Search of the lake
Reservoir with a dam
Water level lowered
to facilitate search
Lake Zoar
8
Search of the lake
Chainsaw
1
Human tissue
Human hair
Blue clothing fibres
Serial number restored Richard
9
2660 strands of bleached hair
Search of the lake
2
69 slivers of human bone
3
5 droplets of human blood
4
2 teeth
5
Helle’s
hair color
O+
One proved to be Helle’s
Chainsaw
1
10
A portion of a human finger
Search of the lake
3 oz human tissue
7
8
1 human fingernail
9
1 portion of human toe nail
10
A truncated piece of human skull
6
11
January 1987
Richard Crafts arrested
Evidence of murder of Helle Crafts
Bail posted at $750 000
How did Richard Crafts kill his wife?
12
Reconstruction of events
Helle beaten to death on early Nov 19
th
?
Police assumption
Body preserved in freezer
1
2
13
Richard Craft’s murder plan
Sent children to sister’s
house in Westport
Made up a story about
electricity problems
Returned to Newtown to
dispose of Helle’s body
Lake Zoar
14
Used chainsaw to cut up Helle’s body
3
Ran Helle’s body parts through woodchipper
4
Helle beaten to death on early Nov 19
th
?
Police assumption
Body preserved in freezer
1
2
Reconstruction of events
Used a pig carcass
15
Re-enactment
Put it through a woodchipper
Effect of woodchipper on a human body?
16
Re-enactment
17
Pig remains
Re-enactment
Consistent with
human remains
found in lake
rental
witness
body parts,
tooth
hair, tissue
(serial number restored)
rental
hair
tissue
fibres (rug)
Richard Crafts sentenced to 50 years in prison
Network of Evidence
18
Types of forensic work
Comparison leading to Association
Locard’s Principle:
19
Summary
Reconstruction & Re-enactment
“Every contact leaves a trace”
4
3
1
2

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