1. Original presentation by Detective Gregory Restina
Mrs. Patricia Nolan Bertino .03
Modified by
Anthony Bertino .04
With materials from Collins, Osselman and Turner

2. Bloodstains are one of the most common types of physical evidence found at a crime scene.

3. Serologists are people who study blood in a forensics laboratory.
This is Dr. Henry Lee, the world’s leading serologist specialist. He has been involved with over six thousand cases within the past forty years.
Serologists are people who study blood in a forensics laboratory.

4. Why study Blood Spatter?
◊ To find out where an assault occurred
◊ To find out the position of the killer during the attack
◊ To find out if the victim was walking or running during the attack
◊ To find out if victims tried to avoid the blows, by holding up object or arms to avoid the hits.
(There would be a gap in the spatter if this happened.)
◊ To find out the type of blood for victim or suspect identification
◊ To find out how long the blood has been there to find a time frame for the attacks

5. Spatter Direction
The tail of the spatter tells us the direction the blood spatter is traveling.

6. Surfaces
If the surface is more rough and porous, the spatter will be absorbed. This picture shows the blood spatter on a carpet.
If the surface is hard, smooth and flat, like tile, the spatter will break up into lots of little drops, and they will be round. This picture shows a close up of one of the drops.

7. The greater the height, the greater the amount of spatter.

8. From close range, the droplets of spatter are closer together
From close range, the droplets of spatter are closer together. A low velocity impact, like a blow from a hammer, will also produce this type of spatter.
From further away, the range of the spatter is more spread out. The darkened edges of the hole show that a bullet was fired to cause the spatter. This is a high velocity impact.

10. Points of Convergence
The red circle shoes the point of convergence.

11. The point where the lines of spatter connect is called the point of convergence. This shows where the blood came from, which is where the victim was at the time of the attack.
In the diagram to the right, strings were used to determine the point of convergence. Wherever the strings connect is where the spatter came from (where the victim was).

12. Patterns of Blood Spatter
There are many different patterns that are created when blood is spilled. Most of these patterns have special names.

13. Arterial Spurting (or Gushing) Pattern - Bloodstain pattern that results from blood exiting the body under pressure from a breached artery. The blood gushes out with the rhythm of the heart.
Cast off pattern- Created when blood is released or thrown from a blood bearing object in motion (for example a knife). These are also called cast-off stains.

14. Drip Pattern- A blood stain pattern which results from dripped blood either from a weapon, victim or sometimes the killer.
Flow pattern- A blood stain pattern which shows a change in shape and direction due to gravity or other forces.

15. Swipe pattern- this pattern is created when blood is transferred from a moving source onto an unstained surface.
Contact Patterns- These types of patterns occur when a wet or bloody surface comes into contact with a second surface.

16. Cast Off Stains
This type of stain can tell how many times a person was hit. The number of stains is always one less than the number of hits, because the first time the weapon hits there is no blood on it.

17. Angles of Spatter
Depending on the angle from which the blood fell the spatter will look different.

18. 60 degrees
10 degrees

19. The steeper the angle, the more elongated the blood stain.
A blood drop falling perpendicular onto a surface (at a 90º angle) will leave a round blood stain where it drops.
A blood drop falling at an angle other than 90º will leave an elongated stain.
The steeper the angle, the more elongated the blood stain.

20. Drying
The higher the temperature, the faster the blood will dry. This is a factor in determining when a killing took place.
The higher the humidity, the slower the drying. The moisture in the air keeps the liquid from evaporating into it. If the humidity was lower, more moisture would be absorbed into the air and so the drying would be faster.

21. The brighter and stronger the glow, the more heavy the blood flow.
Luminol
Luminol is used by investigators when the blood is wiped away and is therefore no longer visible to the naked eye.
Luminol is a chemical that reacts with the hemoglobin in the blood to produce a blue luminescence.
The brighter and stronger the glow, the more recent (and fresh) the blood is.
The brighter and stronger the glow, the more heavy the blood flow.

24. Arterial Gush

25. Passive

28. Transfer

29. Projected

32. Low Velocity Impact

33. Medium Velocity Impact

34. High Velocity Impact

35. Over Hand Swing
Left to Right
High Impact
90 degrees

37. Crime Scene Diagrams & Photos