Crime%20Scene1

Crime%20Scene1 - Crime
Scene
 Today’s
Lecture
...

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Unformatted text preview: Crime
Scene
 Today’s
Lecture
 •  Recognize,
 document,
collect,
 and
preserve
 •  Types
of
evidence
 •  Packaging
 •  Reference
samples
 •  Chain
of
custody
 •  Legal
considerations
 1 Crime
Scenes
Start
with
E!
 •  Physical
evidence:
any
object
that
can
establish
 that
a
crime
has
been
committed
or
can
link
a
 crime
and
its
victim
or
its
perpetrator.
 Perpetrator
 Evidence
 Crime
scene
 Victim
 Crime
Scenes
Start
with
E!
 •  Physical
evidence:
any
object
that
can
establish
 that
a
crime
has
been
committed
or
can
link
a
 crime
and
its
victim
or
its
perpetrator.
 •  Needs
to
be
recognized
as
evidence
first
and
 documented
(notes,
drawings,
measurements,
 photographs)!!!
 •  No
matter
how
good
the
crime
lab
is
the
 evidence
needs
to
be
collected!
(properly)
 •  Preservation
needs
to
be
considered!
 •  The
lab
does
science,
not
magic!
 2 Can
you?
 1.  Recognize
a
crime
has
been
committed
 2.  Secure
and
isolate
the
crime
scene
 –  –  –  –  –  The
1st
police
officer
on
scene
is
responsible
 Clear
the
room
(eliminate
dangers)
and
secure
the
 scene;
victims,
(arrest)
suspects,
witnesses,
etc.
 Medical
need
is
given
priority
over
evidence
 Isolate
an
area
of
sufficient
size
 Keep
unwanted
visitors
out
(including
your
boss,
 the
press,
neighbors,
lookey
loos,
etc.)
 Can
you?
 3.  Evaluation
 –  What
are
we
going
to
do
and
how
are
we
 going
to
do
it?
 –  Walk
through
 –  Crime
scene
boundaries
 –  Entrance
and
exit
 –  Document
and
photograph
(don’t
touch
 anything)
 3 Documentation
 •  Photography
(still
and
video)
 –  Photograph
before
anything
is
touched
or
moved
 –  Photograph
“primary”
area
as
well
as
“secondary”
 area
 –  For
close‐ups,
use
ruler
near
item
as
scale
 •  Sketches
 –  Rough
sketch
to
capture
dimensions
of
scene
and
 location
of
all
relevant
objects
 –  Use
a
legend
in
sketch
to
catalogue
items

 •  Notes
 –  Note
taking
is
a
constant
activity
throughout

 –  Provide
description
and
location
of
physical
 evidence;
time
collected
and
by
whom
 Photography
 •  KEEP
A
PHOTO
LOG!!!
 •  If
any
object
is
moved
because
of
medical
 attention
or
even
on
accident
document
the
 move,
photograph,
and
move
on
(life
isn’t
 perfect)
 •  Move
from
outside
to
in
 –  Points
of
entry
and
exit
 •  Photograph
rooms
not
associated
with
the
 crime
(you
never
know)
 •  What
about
the
crowd
of
on
lookers?
 4 Photography
 •  Overall
concept
applied
 to
the
body,
living
 victims,
and
evidence
 –  Injuries
 –  Items
of
interest
 –  Area
underneath
the
body
 •  Positioning
photos
and
 close
up
photos
should
 use
a
ruler
 •  30%
overlap
of
photos
 Sketches
and
Notes
 •  Don’t
have
to
be
 pretty
 •  Must
contain
the
 case
number,
 location,
time,
and
 name
of
person
 recording
the
 information
 5 6 The
Quest
for
E!
 •  Be
methodical,
systematic
and
thorough
 •  If
possible,
a
single
person
should
supervise
to
 avoid
confusion
and
duplication
of
effort
 •  Type
of
search
depends
on
locale,
size
of
area,
 and
specifics
of
the
crime
 •  Crime
scenes
are
3D
so
remember
to
look
up
 Search
Methods
 •  Zone
 •  Grid
 •  Strip
 •  Spiral
 •  Vehicles
 7 What
Type
of
E?
 •  Evidence
to
be
on
the
lookout
for
depends
on
type
of
crime,
 environment,
etc.
 –  Hit
and
run:
Cross‐transfer
of
evidence
between
car
and
 victim
 •  On
car‐blood,
tissue,
hair,
fibers
 •  On
victim‐paint,
glass
 –  Homicide:
Cross‐transfer
of
evidence
between
assailant
and
 victim
 •  hairs,
fibers,
blood,
fingernail
scrapings,
weapon,
bullet
 casings
 –  Burglary:
Point
of
entry;
tool
marks,
footwear
marks,
 fingerprints
 Typical
E
 Biological
 Biological
fluid:
blood,
 semen,
saliva
 Hair:
human
or
non‐human
 Bones
and
teeth
 Fingerprints
 Organs
and
physiological
 fluids:
autopsy
 Vegetative
matter
 Physical
 Fibers,
fabrics,
glass
 fragments,
paint,
soil
 Drugs

 Explosives
and
post‐blast
 debris

 Petroleum
products
and
 residue:
arson

 Firearms,
ammunition,
and
 gun
shot
residue

 Other
 Impressions:
tire
markings,
 shoe
prints,
depressions
in
 soil
or
snow,
bite
marks

 Tool
marks

 Serial
numbers

 Questioned
documents

 Digital
evidence:
 computers,
cell
phones,
etc
 From
the
massive
to
the
microscopic
or
molecular
level
 8 Interesting
E…
 •  Collect
carriers
of
trace
evidence
 –  Garments
of
victims
and/or
suspect
 • Clothing
should
be
isolated
by
person
 –  Vacuum
sweepings
of
various
locations
in
the
crime
 scene
for
trace
evidence
 •  Dead
body
 –  Clothing,
fingernail
scrapings,
head
and
pubic
hair
 (standards
and
foreign),
blood
(DNA),
cavity
swabs
 (sex‐related
DNA),
injuries
(bullets,
casting
of
 impressions),
hand
swabbing
(for
GSR)

 Dead
Bodies…
 9 Packaging
of
E
 •  Package
to
maintain
the
integrity
 of
the
evidence
 •  Avoid
cross‐contamination;
 package
items
separately
 •  Examples
of
packaging:
 –  Arson
debris:
airtight
containers‐ paint
cans
or
jars
 –  Blood/bodily
fluids:
non‐airtight
 container

 –  Wrap
clothing
items
separately;

 –  try
not
to
disturb
trace
evidence
 –  Package
sweepings
from
 different
areas
separately
 Chain
of
Custody
(CoC)
 •  Crucial
for
court
(it
is
what
gets
the
 evidence
in)
 •  Every
person
who
handled,
transported
 or
examined
evidence
must
be
accounted
 for
 •  Typically
as
a
simple
as
maintaining
a
 sequential
log
of
who
had
custody
of
a
 specific
item
for
what
period
of
time
 10 Standards
and
References
 •  Soil,
hair,
fiber,
paint,
bullets,
DNA,
etc.
requires
 comparison
with
a
“standard
or
reference”
to
 determine
if
there
is
“common
origin”
 •  Quantity
and
quality
of
reference
standard
 increases
the
evidential
value
of
crime
scene
 evidence
 •  Substrate
controls:
sample
surfaces
nearby
that
 are
thought
not
to
contain
evidence
 –  Arson
–
opposite
of
where
the
gasoline
was
 poured
(or
believed
to
be
poured)
 Evidence
Submission
 •  Law
enforcement
agent
or
mail
system
 (FedEx,
UPS,
USPS,
DHL)
that
has
tracking
 in
place
with
required
signatures
 •  Make
sure
you
can
mail
your
evidence!
 –  Live
ammunition,
flammables,
explosives,
 etc.
 11 Evidence
Submission
 •  Must
have
some
information
in
the
box
stating
 what
it
is
(unique
case
identifiers),
what
test
are
 to
be
performed,
and
what
to
do
with
the
 evidence
when
analysis
has
finished
 –  Typically
standardized
forms
issued
by
the
 laboratory
 •  All
seals
must
be
intact
and
information
must
 match
otherwise
the
evidence
is
returned
to
 sender
 Evidence
Submission
 •  Evidence
must
be
properly
packaged
to
 prevent
harm
to
the
examiner
 –  Syringes
 –  Knives
 –  Guns
 –  Biohazard
material
 12 Crime
Scene
Attire
 •  Clothing
to
protect
you
as
well
 as
the
crime
scene
 –  Double
gloved
latex
 gloves
 –  Tyvex
show
covers
 –  Tyvex
suits
 –  Particle
masks,
goggles,
 SCBA,
etc.
 •  Dispose
of
contaminated
 clothing
appropriately
 •  GLP
–
no
eating,
smoking,
 drinking,
make‐up
 •  Decon
things
that
cannot
be
 thrown
out
 13 14 Legal
Issues
 •  Fourth
Amendment:
The
right
of
the
people
to
be
 secure
in
their
person,
houses,
papers,
and
effects,
 against
unreasonable
searches
and
seizure,
shall
not
be
 violated,
and
no
warrants
shall
issue,
but
upon
probable
 cause,
supported
by
oath
or
affirmation,
and
particularly
 describing
the
place
to
be
searched,
and
the
persons
or
 things
to
be
seized.

 •  Allowances
for
warrantless
searches:
 –  Emergencies
 –  To
prevent
immediate
loss
or
destruction
of
evidence
 –  Search
of
a
person
and
property
within
immediate
 control
of
the
person
provided
it
is
made
incident
to
 a
lawful
arrest
 –  Search
is
made
by
consent
of
the
parties
 15 ...
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