CSI Lesson Two (3/8/2011)

Blood Splatter:
-Pattern left behind by falling or projected drops of blood can help investigators ro determine how and where the crime was committed. Therefore, blood drops and stains are usually examined closely before the evidence is collected. There is lots of physics (kinematics) behind it.
Look at the various blood splatters below and guess how they are formed.
Blood Splatter ONE:


Blood Splatter TWO:


Blood Splatter THREE:


Blood Splatter FOUR:


Blood Splatter Pattern from a Laboratory Experiment by Mr Leong TK & Chua HL

Answer the following questions in your journal:
1. What is the shape of blood splatter?
Blood splatter is round. Blood splatters vary in degree of "ovalness", sometimes being elongated.
2. Describe any other characteristic of the splatter.
Blood splatter is most concentrated at the centre of splatter, making it darker when dried. Blood splatter also does not have smooth sides but rather jagged edges.
3. What are the factors that affect the shape of the blood splatter? Name as many as possible.
-Angle of elevation
-Distant from its origin and the surface
-Surface of which the blood dropped on
-Force--> which in turn affects velocity of the blood
4. Generate some hypothesis from the blood splatter patterns observed above.
-The higher the angle of elevation, the longer the blood splatter.
-The higher the angle of elevation, the narrower and elongated the blood splatter.
-The further the distance from the origin and surface of which the blood was dropped on, the bigger the diameter of the blood splatter.
Blood Splatter Experiment:
Conducting the experiment


Our results



Raw data of Blood splatter experiment:
Height at which blood is dripped from(10cm, 30cm, 60cm, 100cm, 150cm)
A10: 0.9cm

B10: 1.1cm

A30:1.0cm

B30: 1.1cm

A60: 1.1cm

B60:1.2cm

A100: 1.2cm

B100: 1.2cm

A150: 1.3cm

B150: 1.4cm




Angle of elevation (10,30,50,70,100 degrees)

P10: 1.1cm

Q10: 1.2cm

P30: 1.2cm

Q30: 1.3cm

P50: 1.3cm

Q50: 1.3cm

P70: 1.2cm

Q70: 1.2cm

P100: 1.3cm

Q100: 1.3cm

Blood splatter Activity(spraying paint on bucher sheets):