By Sebastian Restrepo
The Use of Blood in Forensics
Teens Life is Saved when Blood Splatter Evidence Proves she could not have Killed her parents
For one "lucky" teen, blood was the "aha" evidence that saved her life. A famous murder case from Idaho put the daughter of a murdered couple on trial. Retired crime lab technician Michael Howard testified that whoever shot Diane and Alan Johnson at close range on September 2, 2003, would have been hit by a "rain" of blood spatter.
However, Sarah Johnson, 18, who faced life in prison for two counts of first-degree murder, did not have her parents' blood on her that morning, according to Howard.
Investigators found out later that Sarah did not kill the two parents, and that the misting pattern of blood indicated that the shooter was wearing Sarah's robe.
Interesting Facts about Blood
- Blood makes up about 7% of the weight of human body.
- Blood cells float in a yellow liquid called blood plasma.
- There are 150 billion red blood cells in one ounce of blood.
- The most common type of blood in the united states is O Positive, while the least common blood type is AB negative.
This is any type of specific antigen present on the surface of red blood cells.
A colorless cell that circulates in the blood and body fluids and is involved in counteracting foreign substances and disease (a white blood cell)