Bloodstain Patterns

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Bloodstain Patterns
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Bloodstain Patterns

• The location, distribution, and appearance of
  bloodstains is often useful in reconstructing the
  events of a crime
• The analysis of bloodstains can be very complex
  and depends on a number of factors.
• The position and shape of blood patterns is
  analyzed

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Surface Texture

• In general, the harder and less porous the
  surface, the less spatter

Porous surface
Hard surface
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Direction of Travel

• The shape of a blood stain can indicate the
  direction that blood droplets were moving when
  they hit the ground
• The pointed end faces the direction of travel

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The Angle of Impact

• The shape of a bloodstain is determined by the
  angle in which it hits the surface.
• A drop of blood hitting the surface at a right
  angle (90o) forms a circular stain.
• As the angle decreases, the stain elongates.
• How Bloodstain Patterns are formed

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Angle of Impact
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The Origin of Blood Spatter

• The origin of blood spatter by drawing lines
  along the long axis of several stains and finding
  the point at which they intersect

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The Origin of Blood Spatter