Bloodstain Evidence Test 1
1. Bloodstain Pat- identification and individualization of blood is cojoined
tern Analysis focuses on size, shape, and distribution of bloodstains
resulting from bloodshed to determine related activities
and mechanisms
2. BPA objectives help with scene construction
-areas of convergence and origin
-type and direction of impact that produced stain or spatter
-mechanism by which spatter produced
Helps to answer the who, what, when and where
3. scientific ap- adhere to scientific method (biology, physics, mathemat-
proach ics)
proficiency
-formal instruction
personal experimentation
-actual case work
stay within what can be proven sicentifically
4. Macdonell responsible for Modern BPA and instrumental in formation
of the international association of BPA
IABPA (750 members, countries around the world)
5. low velocity im- -source of blood is subjected to force with velocity up to 5
pact blood spat- ft/sec
ter - primary stains measure 4mm or greater
6. medium veloci- -source of blood subjected to force with velocity up of 5 to
ty impact blood 25 ft sec
spatter -stain diameters range from 1 to 3 mm
-beatings and stabbings
7. high velocity im- -source of blood is subjected to force with velocity greater
pact blood spat- than 100 ft/sec
ter
, Bloodstain Evidence Test 1
-less than 1 mm
-gunshot injuries
8. discontinuation overlap between stain sizes
mechanisms other than beatings/stabbings/ and gunshots
frequently produce stains in same size ranges
9. classification size, shape, location, concentration, and distribution (pas-
sive, spatter, altered stains)
10. Passive Stains Drops, Flows, and Pools, results from gravity acting
-large volume, transfer
patterns whose physical features indicate they were creat-
ed without any significant outside force other than gravity
and friction
11. spatter stains Bloodstains resulting from blood drops distributed through
the air due to an external force applied to a source of liquid
blood
-impact mechanism, secondary mechanism, projection
mechanism
directionality, vary in size, and are associated with a
source of blood being subjected to an external forces, in
addition to gravity and function
12. altered stains Physically or physiologically changed
-clotted
-diluted
-diffused
-insects
-sequenced
-voids
patterns whose appearance indicates the blood and/or
pattern has undergone a physical and/or physiologic al-
teration
13. Frye Standard A test to determine the admissibility of scientific evidence.
, Bloodstain Evidence Test 1
14. Daubert Stan- A test of scientific acceptability applicable to the gathering
dard of evidence in criminal cases.
-has scientific theory been empirically tested?
-has scientific theory been subjected to peer review and
publication?
potential error rate?
-experts qualification
-sufficient clarity?
15. SWGSTAIN Scientific Working Group on Bloodstain Pattern Analysis
funded by the FBI
16. circulation blood pumps from heart
-4 chambers and 4 valves
-pumps through 2 large arteries and smaller arteries
called arterioles
-pressure by heart contraction and dilation of arterioles
-pressure (mm Hg)
17. systolic pressure pressure during contraction of heart (systole of the heart)
>160
18. diastolic pres- pressure when heart relaxed (diastole of the heart) >90
sure diastolic hypertension
19. normal pressure 115/70
20. hypotension or below 100 systolic or <50 diastolic= hypotension or shock
shock
21. vessels oxygenated blood flows through arteries and arterioles
then into capillaries
-after flow from capillaries blood flows to venules, then
large veins, then back to heart
-some propulsion from heart, gravity and contraction of
large muscles
-leg veins have bicuspid valves act as pump to direct blood
back to heart and prevent backflow
1. Bloodstain Pat- identification and individualization of blood is cojoined
tern Analysis focuses on size, shape, and distribution of bloodstains
resulting from bloodshed to determine related activities
and mechanisms
2. BPA objectives help with scene construction
-areas of convergence and origin
-type and direction of impact that produced stain or spatter
-mechanism by which spatter produced
Helps to answer the who, what, when and where
3. scientific ap- adhere to scientific method (biology, physics, mathemat-
proach ics)
proficiency
-formal instruction
personal experimentation
-actual case work
stay within what can be proven sicentifically
4. Macdonell responsible for Modern BPA and instrumental in formation
of the international association of BPA
IABPA (750 members, countries around the world)
5. low velocity im- -source of blood is subjected to force with velocity up to 5
pact blood spat- ft/sec
ter - primary stains measure 4mm or greater
6. medium veloci- -source of blood subjected to force with velocity up of 5 to
ty impact blood 25 ft sec
spatter -stain diameters range from 1 to 3 mm
-beatings and stabbings
7. high velocity im- -source of blood is subjected to force with velocity greater
pact blood spat- than 100 ft/sec
ter
, Bloodstain Evidence Test 1
-less than 1 mm
-gunshot injuries
8. discontinuation overlap between stain sizes
mechanisms other than beatings/stabbings/ and gunshots
frequently produce stains in same size ranges
9. classification size, shape, location, concentration, and distribution (pas-
sive, spatter, altered stains)
10. Passive Stains Drops, Flows, and Pools, results from gravity acting
-large volume, transfer
patterns whose physical features indicate they were creat-
ed without any significant outside force other than gravity
and friction
11. spatter stains Bloodstains resulting from blood drops distributed through
the air due to an external force applied to a source of liquid
blood
-impact mechanism, secondary mechanism, projection
mechanism
directionality, vary in size, and are associated with a
source of blood being subjected to an external forces, in
addition to gravity and function
12. altered stains Physically or physiologically changed
-clotted
-diluted
-diffused
-insects
-sequenced
-voids
patterns whose appearance indicates the blood and/or
pattern has undergone a physical and/or physiologic al-
teration
13. Frye Standard A test to determine the admissibility of scientific evidence.
, Bloodstain Evidence Test 1
14. Daubert Stan- A test of scientific acceptability applicable to the gathering
dard of evidence in criminal cases.
-has scientific theory been empirically tested?
-has scientific theory been subjected to peer review and
publication?
potential error rate?
-experts qualification
-sufficient clarity?
15. SWGSTAIN Scientific Working Group on Bloodstain Pattern Analysis
funded by the FBI
16. circulation blood pumps from heart
-4 chambers and 4 valves
-pumps through 2 large arteries and smaller arteries
called arterioles
-pressure by heart contraction and dilation of arterioles
-pressure (mm Hg)
17. systolic pressure pressure during contraction of heart (systole of the heart)
>160
18. diastolic pres- pressure when heart relaxed (diastole of the heart) >90
sure diastolic hypertension
19. normal pressure 115/70
20. hypotension or below 100 systolic or <50 diastolic= hypotension or shock
shock
21. vessels oxygenated blood flows through arteries and arterioles
then into capillaries
-after flow from capillaries blood flows to venules, then
large veins, then back to heart
-some propulsion from heart, gravity and contraction of
large muscles
-leg veins have bicuspid valves act as pump to direct blood
back to heart and prevent backflow
