Blood Spatter Analysis Quizziz

What are questions that BPA analysts called on to answer?

• Where did the blood come from?

• What caused the wounds?

• What direction did the blood come from?

• Does the blood stain evidence support or refute witness statements?

This pattern results from:

• Multiple Stab Actions

• Arterial Spray

• High Velocity Blood Spatter

• Expirated Spatter

Answer explanation

This results from the spurt of blood released when a major artery is severed.

The rising and falling is consistent with the heart beating.

Wipe and Swipe Patterns are both transfer stains. Based on the video, what are characteristics of a wipe pattern?

• skeletonized ring

• something disturbed the blood after it started to dry

• does not form a skeletonized ring

• has a feathered edge

Answer explanation

Swipe vs Wipe

https://www.youtube.com/watch?v=TrXj3N26aP4&t=1s

What typeof spatter is created from a gunshot?

• arterial spray

• BPA

• high impact

• expirated spatter

This picture shows:

• cast off

• void

• expirated

• arterial

At what height does the diameter of a blood drop stop changing?

• .8 m

• 1.0 m

• 1.8 m

• 2.8 m

Answer explanation

Due to the

density of blood

AND

a viscosity that is 6X greater than water

AND

gravity (9.8 m/s2)

a drop of blood will no longer change in size after 1.8 m (6 ft).

The drop shown above would have more than likely been dropped from an angle of 

• 90

• 30

• 50

• 10

Answer explanation

This is what your blood angle lab images should have looked like.

At 90 degrees it is round. As the angle. Gravity then takes over as angle is changed to increase the length dimension and lengthen the tail.

Tags

NGSS.HS-PS2-1

Blood spatter on non porous surfaces (like tile) will have spines and satellites.

• True

• False

Answer explanation

This picture shows

• castoff

• splash

• passive

• medium velocity

What is true about the blood pattern pictured?

• The result of passive drops that have dried completely

• constistent with the outliers of arterial spray

• Air was mixed in with blood

• consistent with expirated spatter

Answer explanation

In the Sherlock Holmes Spatter Case Studies, Dr. Henry Lee determined that such drop had resulted from an individual who vomited or coughed up blood that was mixed with air.

The air formed a bubble and when the bubble popped it left what he called a "ghost" pattern.