Blood spatter analysis can provide valuable insights into violent crime scenes. The location, distribution, and appearance of bloodstains can be used to interpret events and reconstruct what happened. Different types of bloodstains - including passive drops, transfers, projections, cast-off, and arterial spray - can indicate the direction of blows, positions of victims and assailants, and number of wounds. Careful documentation of bloodstain patterns is important for accurate interpretation and reconstruction of crime scene events.
This presentation is about the Gun Shot Residue which is a prime evidence in the investigation of crimes involving a use of firearm. It will inform the viewer about the composition, relevance and various chemical and instrumental methods employed for its analysis.
It is the interpretation of bloodstains at a crime scene in order to recreate the actions that caused the bloodshed. Analysts examine the size, shape, distribution and location of the bloodstains to form opinions about what did or did not happen.
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A detailed fingerprint presentation. Fingerprint is one of the most important criminal investigation tools due to their two significant features- uniqueness and persistence. The unique features of friction ridge skin persist from before birth, i.e. during fetal development to the decomposition after death...
Alteration is defined as any change to a document which gives it a different effect from
that it originally possessed. If change is made after execution of a document and without
the consent of the other party or concerned person, then such change is called fraudulent
alteration. Document examiners must be able to identify documents that were altered to change the conditions of a contract or other legal entity.
Alterations can take the form of erasures and replacement and/or insertion of material into a document.
This presentation is about the Gun Shot Residue which is a prime evidence in the investigation of crimes involving a use of firearm. It will inform the viewer about the composition, relevance and various chemical and instrumental methods employed for its analysis.
It is the interpretation of bloodstains at a crime scene in order to recreate the actions that caused the bloodshed. Analysts examine the size, shape, distribution and location of the bloodstains to form opinions about what did or did not happen.
Fingerprint - Everything You Need To Know About FingerprintsSwaroopSonone
A detailed fingerprint presentation. Fingerprint is one of the most important criminal investigation tools due to their two significant features- uniqueness and persistence. The unique features of friction ridge skin persist from before birth, i.e. during fetal development to the decomposition after death...
Alteration is defined as any change to a document which gives it a different effect from
that it originally possessed. If change is made after execution of a document and without
the consent of the other party or concerned person, then such change is called fraudulent
alteration. Document examiners must be able to identify documents that were altered to change the conditions of a contract or other legal entity.
Alterations can take the form of erasures and replacement and/or insertion of material into a document.
FSB05
b l o o d s patt e r
Properties of blood
Teacher Background Information
Blood is considered to be a fu
with no fxed shape and is su
pressure. A fuid can be either
liquid is a fuid that has a fxed
fuid that can expand indefni
Viscosity
Viscosity is defned as a fuid’s
more viscous a substance is, th
fow. The SI unit for viscosity is
viscosity is compared to water
one. Blood is thicker than wate
due to the cellular component
viscosity of some common su
id. A fuid is a substance
bject to external
a liquid or a gas. A
volume while a gas is a
tely.
resistance to fow. The
e more slowly it will
the Pascal second. Fluid
that has a viscosity of
r and is viscous primarily
(see FSB04). The
bstances, including blood:
Liquid Viscosity (mP·s-1)
Milk (25oC) 3
Blood (37 oC) 3-4
Glycerin (20 oC) �420
Mercury (�5 oC) �.55
Water (20 oC) �.0
Water (�00 oC) 0.28
http://hypertextbook.com/physics/matter/viscosity/
Surface tension
Surface tension is the force that pulls the surface
molecules towards the interior of a liquid, decreasing
the surface area and causing the liquid to resist
penetration or separation.
Surface tension is the tendency of the surface of a
liquid to contract to the smallest area possible. The
fuid is able to do this as the cohesive forces are
stronger on the surface of liquids as there are no
neighbouring molecules above. As a result there are
stronger attractive forces between molecules and their
nearest neighbours on the surface; the surface tension
force actually exerts an upward force. Surface tension is
like having an elastic flm over the surface.
Figure �: A water strider standing on water.
Citation: Water strider: David Cappaert, www.insectimages.org
In Figure �, the surface tension of the water allows the
water strider to walk on the water without sinking.
This is because the upward force from surface tension
balances the insect’s weight.
Defnition of surface tension: the surface tension γ is
the magnitude F of the force exerted parallel to the
surface of a liquid divided by the length L of the line
over which the force acts:
γ = F _
L
Surface tension is measured in force per unit length:
newtons per metre: (N·m-�). The old unit is dynes per cm.
The surface tension of some common liquids:
Liquid Surface tension N·m-�
Benzene (20oC) 0.029
Blood (37 oC) 0.058
Glycerin (20 oC) 0.063
Mercury (20 oC) 0.47
Water (20 oC) 0.073
Water (�00 oC) 0.059
http://www3.interscience.wiley.com:8100/legacy/college/
cutnell/0471713988/ste/ste.pdf
�
http://www3.interscience.wiley.com:8100/legacy/college
http:www.insectimages.org
http://hypertextbook.com/physics/matter/viscosity
http://www3.interscience.wiley.com:8100/legacy/college
http:www.insectimages.org
http://hypertextbook.com/physics/matter/viscos ...
Embracing GenAI - A Strategic ImperativePeter Windle
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This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
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A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
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This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
2. General Bloodstain Features
Bloodstain patterns deposited on floors, walls,
bedding, and other relevant objects can provide
valuable insights into events that occurred
during the commission of a violent crime.
The crime scene investigator must remember
that the location, distribution, and appearance of
bloodstains and spatters may be useful for
interpreting and reconstructing the events that
produced the bleeding.
3. General Bloodstain Features
The information one is likely to uncover as a result of
bloodstain pattern interpretation includes:
-- The direction from which blood originated
-- The angle at which a blood droplet struck a surface
-- The location or position of a victim at the time a
bloody wound was inflicted
-- The movement of a bleeding individual at the crime
scene
-- The approximate number of blows that struck a
bleeding victim
-- The approximate location of an individual delivering
blows that produced a bloodstain pattern
4. Importance of Blood Spatter
More than just DNA
Can be used to reconstruct the crime
Can place a suspect at the scene of the
crime
Has been used to gain acquittals
5. Effects of Surface Texture
Surface texture and the stain’s shape,
size, and location must be considered
when determining the direction, dropping
distance, and angle of impact of a
bloodstain.
Surface texture is of paramount
importance. In general, the harder and
less porous the surface, the less spatter
results.
6. Categories of Blood Stains
Passive: drops formed or created by
gravitational force alone
Transfer: created by a wet, bloody surface
coming into contact with another surface
often leaving a recognizable image of all
or a portion of the initial surface
Projected: created by a force or action
greater than that of gravity
7. Passive Stains
Affected primarily by
surface texture and
height of droplet
The greater the
distance from origin
to surface the more
spatter created
8. Transfer Pattern
A contact or transfer pattern is created when
an object with blood on it touches one that does
not have blood on it.
Simple transfer patterns are produced when the
object makes contact with the surface and is
removed without any movement of the object.
The size and general shape of the object may be
seen in a simple transfer.
Other transfers may be caused by movement of
the bloody object across a surface.
9. Transfer Stains
Can create measurable images such as
footprints
Can leave an identifiable impression such
as a finger or palm print
11. Projected Blood Stains
Size, shape, and
number of stains is
dependant on the
amount of force
exerted on the blood
source
Often creates cast off
patterns
12. Impact Spatter
Low Velocity: Up to 5 ft/sec
Stains 4mm or greater
Medium Velocity: 5-25 ft/sec
Stains 1-4mm
High Velocity: 100+ ft/sec
Stains less than 1mm usually mist like
appearance
16. Impact Bloodstain Spatter
Patterns
Impact spatter occurs when an object
impacts a source of blood.
Forward spatter is projected outward
and away from the source.
Back spatter, sometimes called blow-
back spatter, is projected backward from
the source,
17.
18. Gunshot Spatter
Gunshot spatter is characterized by fine forward
spatter from an exit wound and back spatter
from an entrance wound. However, the gunshot
produces only back spatter if the bullet does not
exit the body.
Depending upon the distance from the victim
that the gun was discharged, some back spatter
may strike the gunman and enter the gun
muzzle. This is called the drawback effect.
19.
20.
21. Cast-off Spatter
A cast-off pattern is created when a blood-
covered object flings blood in an arc onto a
nearby surface.
This kind of pattern commonly produced by a
bloody fist or weapon between delivering blows.
The features of the cast-off pattern are affected
by the size of the object, the amount of blood,
and the direction the object was moving.
By counting and pairing forward/backward
patterns, one may determine the minimum
number of blows delivered.
22. Evidence Derived from Cast Off
Patterns
Position of assailant and victim during
attack
Direction weapon traveled
Approximate height of attacker
Impact angle of spatter
Point of convergence
23.
24. Arterial Spray Spatter
Arterial spray spatter is created when a
victim suffers an injury to a main artery or
the heart, and the pressure of the
continuing pumping of blood causes blood
to spurt out of the injured area.
The site of the initial injury to the artery
can be found where the pattern begins
with the biggest spurt. The trail away from
this point shows the victim’s movement.
The oxygenated blood spurting from the
artery tends to be a brighter red color
than blood expelled from impact wounds.
25. Cast Off Vs. Arterial Spurting
Arterial spurting is created
Cast off is created by force or
when blood exits the body
action greater than gravity
under pressure from a
compromised artery
26. Expirated Blood Patterns
An expirated blood pattern is created by
blood that is expelled from the mouth or nose
from an internal injury.
The presence of bubbles of oxygen in the drying
drops or a lighter color as a result of dilution by
saliva can differentiate a pattern created by
expirated blood.
The presence of expirated blood gives an
important clue as to the injuries suffered and the
events that took place at a crime scene.
27.
28. Void Pattern
A void is created when an object blocks
the deposition of blood spatter onto a
target surface or object and the spatter is
deposited onto the object or person
instead.
The blank space on the surface or object
may give a clue as to the size and shape
of the missing object or person.
Voids may be applicable for establishing
the body position of the victim or assailant
at the time of the incident.
29.
30. Flow Patterns
Flow patterns are made by drops or large
amounts of blood flowing by the pull of gravity.
“Active” flows are formed by blood coming from
an actively bleeding wound.
“Passive” flows originate with blood deposited
on a surface such as an arterial spurt.
The flow direction may show movements of
objects or bodies while the flow was still in
progress or after the blood dried.
Interruption of a flow pattern may indicate the
sequence and passage of time between the flow
and its interruption.
31.
32. Pool Patterns
A pool of blood occurs when blood collects in a
level and undisturbed place.
Blood that pools on an absorbent surface may
be absorbed throughout the surface and diffuse.
The approximate drying time of a pool of blood
is related to the environmental condition of the
scene. By experimentation an analyst may be
able to reasonably estimate the drying times of
stains of different sizes.
33.
34. Skeletonization
The phenomenon of skeletonization occurs
when the edges of a stain dry to the surface.
This usually occurs within 50 seconds of
deposition of droplets, and longer for larger
volumes of blood.
After this time, if the bloodstain is altered by a
contact of wiping motion, the skeletonized
perimeter will be left intact.
Knowing the skeletonization time, an
investigator determine the timing of movement
or activity.
35.
36. Trail Pattern
A trail pattern is a series of drops that are
separate from other patterns, formed by blood
dripping off an object or injury.
The stains form a kind of line or path usually
made by the suspect after injuring or killing the
victim or injuring themself.
The pattern may show movement, lead to a
discarded weapon, or provide identification of
the suspect by his or her own blood.
The shape of the stains in trail patter can help
investigators determine the direction and speed
at which a person was moving.
37.
38. Determining the Impact Angle
Pointed end of blood
stain always faces its
direction of travel
Measure the degree of
circular distortion to
determine impact angle
As the angle decreases
the stain becomes
increasingly elongated
39. Area of Convergence
The area of convergence is the point on
a two-dimensional plane from which the
drops in an impact pattern originated.
This can be established by drawing
straight lines through the long axis of
several individual bloodstains, following
the line of their tails.
40. Point of Convergence Cont.
Forensic Team uses Illustration of
string to identify origin Convergence
41. Point of Convergence
Point of convergence
is identified by
drawing a line
through the long axis
of a stain
The point at which
the stains converge is
the blood spatter
origin
42. Area of Origin
The area of origin of an impact
bloodstain pattern is the area in a three-
dimensional space from which the blood
was projected.
This will show the position of the victim or
suspect in space when the stain-producing
event took place.
The string method is commonly used at a
crime scene to approximate the position of
the area of origin using found angles of
impact of individual stains in the pattern.
43.
44. Documenting Bloodstain Evidence
Investigators should note, study, and
photograph each pattern and drop to accurately
record the location of specific patterns and to
distinguish the stains from which laboratory
samples were taken.
In photographs specific techniques are used to
document bloodstain patterns.
-- The grid method involves setting up a grid of
squares of known dimensions over the entire
pattern.
-- The perimeter ruler method involves setting
up a rectangular border of rulers around the
pattern and then placing a small ruler next to
each stain.
45. Interpreting Bloodstain Evidence
Some jurisdictions have a specialist on
staff who will decipher patterns either at
the scene or from photographs at the lab.
However, it is important that all personnel
be familiar with patterns to properly
record and document them for use in
reconstruction.