Blood Spatter
October 3, 2014
Early on the morning of July 4, 1954
police received a call from Dr. Sam
Sheppard.
He reported that his wife had been
killed the night before.
Sam & Marilyn Sheppard
Sam Sheppard Case
Sam’s Story
• He went to sleep on the couch
• Heard his wife shout “Sam”and
awoke
• Found a person standing by his
wife’s bed. They struggled, Sam
was hit on the back of the neck,
and lost consciousness.
• When he awoke, he found his wife
covered in blood. He took her
pulse and found that she was dead.
Marilyn, partially undressed and
covered in blood.
Sam Sheppard Case
Sam’s Story
• When he regained consciousness, the
intruder was gone.
• He checked on sleeping son next door
– he was fine.
• Went downstairs and saw intruder
leaving.
• Chased and battled the “tall bushyhaired” intruder on the beach, was
choked, and again lost consciousness
• Awoke in the morning, wet & missing
his shirt and watch.
Sheppard (?) with a neck brace
Sam Sheppard Case
Police investigation
• Marilyn was found in bed,
with her clothes partially
removed and covered in blood
• More than 20 blows to her
head
• Appearance of staged robbery
Crime scene sketch of Sheppard home
Sam Sheppard Case
Police investigation
• Marilyn was found in bed,
with her clothes partially
removed and covered in blood
• More than 20 blows to her
head
• Appearance of staged robbery
Quote from Marilyn’s friend’s
husband, who was allowed to view
the scene:
"Oh my God. It looks like
someone stood in the middle of the
room with a great big can of red
paint and a brush and flicked it all
around. This wasn't a couple of
blows. Oh no. Whoever did it,
they had to be out of their mind.“
Sam Sheppard Case
1954 Trial
• Police quickly concluded the Sheppard
killed his wife and (perhaps) did a
somewhat sloppy job examining the
evidence
• The case garnered a lot of publicity, and the
press was very hostile to Sheppard
• The trial had “carnival-like atmosphere”
and the defense offered little evidence other
than Sam’s story and injury.
• Convicted and sentenced to life in prison.
Sam Sheppard Case
Supreme Court Verdict
• In 1966 the Supreme Court overturned Sheppard’s
conviction, arguing that he did not receive a fair trial due to
the publicity surrounding the trial
Sam Sheppard Case
1966 Retrial
• Respected criminalist Dr. Paul Kirk re-examined the
blood spatter evidence and testified for the defense
• Blood spatter consistent with left-handed killer (Sam
Sheppard is right-handed)
• Blood on Sheppard’s watch and clothing was transferred
blood not back spatter
• Sheppard was pronounced not guilty.
The End
… or is it?
Sam Sheppard Case
2000 Civil Trial
• In 2000, Sam Sheppard’s son sued the county for
wrongful imprisonment.
• The jury sided with the county, and 6 of 8 jurors said they
believed Sheppard to be the murderer.
So … is he guilty??
You decide!
Sam Sheppard Case
Blood spatter – the patterns left on a crime scene by blood – can
be used to help reconstruct the events of a crime.
By observing spatter, you can determine
• The direction of travel
• The angle of impact
• The position origin
• The droplet’s speed
What can you learn from
blood spatter?
Passive blood
• Blood drops that form by the force of gravity,
alone.
• Example: Blood dripping or oozing from a wound
or a weapon
A murder throws a bloody
knife into the bushes,
leaving blood spatter on the
Projected blood
grass. something
Is this passive
• Blood drops that form when
otherblood
than
projected
gravity applies a force or
to the
blood.blood. Why?
• Example: Arterial pressure, blunt force trauma,
gunshot, etc.
Classifying Spatter
Talk with a partner, and take a guess …
How will each of these factors affect passive blood spatter
patterns?
1. Distance of dropping
2. Angle of impact
3. Surface of impact
Passive Blood Spatter Patterns
Distance of Dropping
• Passive blood falls due to gravity
• Accelerates until reaching terminal velocity
• Higher the fall  faster the velocity of impact (up to a point)
• Terminal velocity is ~25 ft per second, occurs with fall of ~5ft
• Faster velocity / Higher fall = larger diameter of drop.
Which drop fell from
the greatest height?
The drop on the upper left.
Passive Blood Spatter Patterns
E
B
D
A
C
F
Match each stain from the height with the heights at which they
were dropped. Assume the same amount of blood fell with each
drop
Heights: 1.5 ft, 2 ft, 3 ft, 5 ft, 7 ft, 10 ft
Passive Blood Spatter Patterns
E
B
D
A
C
F
Match each stain from the height with the heights at which they
were dropped. Assume the same amount of blood fell with each
drop
Heights: 1.5 ft (E), 2 ft (C), 3 ft (B), 5 ft (?), 7 ft (?), 10 ft (?)
Why don’t A, D, and
F vary much in size?
Passive Blood Spatter Patterns
E
B
D
A
C
F
Match each stain from the height with the heights at which they
were dropped. Assume the same amount of blood fell with each
drop
Heights: 1.5 ft (E), 2 ft (C), 3 ft (B), 5 ft (?), 7 ft (?), 10 ft (?)
Why don’t A, D, and F vary much in
size? Blood reaches terminal velocity at
about ~5 ft.
Passive Blood Spatter Patterns
Angle of Impact
• Drops that hit at a 90O angle
(i.e. straight down) form an
even circle.
• Drops that hit at other angles
form an elongated oval
• The longer the oval, the
shallower the angle of impact
Passive Blood Spatter Patterns
Angle of Impact
The angle of impact can be
calculated using the formula:
Angle of impact = arcsine (
𝑤𝑖𝑑𝑡ℎ
)
𝑙𝑒𝑛𝑔𝑡ℎ
3 cm
5 cm
Angle of impact = arcsine (3/5) = 37 degrees
Passive Blood Spatter Patterns
Angle of Impact
Angle of impact = arcsine
You do: Find the angles.
𝑤𝑖𝑑𝑡ℎ
(
)
𝑙𝑒𝑛𝑔𝑡ℎ
Which drop had a greater angle of impact? The one on the left
What does it mean to have a greater angle of impact? The greater
2 cm
30
degrees
4 cm
3 cm
49
degrees
4 cm
the angle, the
more
perpendicular
(straight
down) the
drop lands.
Passive Blood Spatter Patterns
Surface of Impact
Drops falling onto smooth, non-porous
surfaces have smooth edges (they don’t
splash).
Drops falling onto rough surfaces produce
spiny / irregular stains and possibly
satellite spatter.
Spatter on tile
Satellite spatter are the small drops that
surround a central drop. They form when
the blood splashes after hitting the surface.
Spatter on wood
Passive Blood Spatter Patterns
Think, Pair, & Share.
What can you tell me about
this spatter?
• What were our objectives today? How did we meet
them?
• What was our learner profile trait and how did we use it?
• How does what we did today address our unit objective?
Closure
• Draw some blood spatter patterns in the below. Write a
short paragraph describing the spatter. Use at least 5 of
the following vocab words in your paragraph: passive
blood, projected blood, angle of impact, velocity of
impact, terminal velocity, surface of impact, satellite
spatter.
Exit Ticket