how different blood splatters are formed! (research)

Blood dropped in different ways have different blood splatters! General rules: Higher distance, larger drop. Faster speed, larger drop. 


(summarised from http://science.howstuffworks.com/bloodstain-pattern-analysis2.htm)


Dripping/Low-Velocity Splatters
These are also known as a low-velocity spatter, the result of dripping blood. 


Force of impact: five feet per second or less
Size of the droplets: between four and eight millimeters (0.16 to 0.31 inches). This When it occurs: often after a victim initially sustains an injury, not during the infliction of the injury itself. 


Examples:

• Victim is stabbed and then walks around bleeding: passive spatters. 
• Pools of blood around the body of a victim and transfers (impressions left by weapons, or smears and trails left by movement). 
• Some injuries (ie. bleeding sustained from a punch).

Medium-velocity Spatters
Force of impact: 5 to 100 feet per second
Size of droplets: diameter is usually no more than four millimeters. 
When it occurs: 1) Caused by a blunt object, such as a bat or an intense beating with a fist, 2) stabbing. 


Unlike with a low-density spatter, when a victim is beaten or stabbed, arteries can be damaged. If they're close to the skin, the victim bleeds faster and blood can spurt from wounds as his or her heart continues to pump. This results in a larger amount of blood and a very distinctive pattern. 


High-velocity Spatters
Force of Impact: more than 100 feet per second 
Size of droplets: look like a fine spray of tiny droplets, less than one millimeter in diameter. 


*Bullet wounds are unique because they can have both back and front spatters, or just back spatters. This depends on whether the bullet stopped after entering the victim's body or traveled through it. In most cases, the back spatter is much smaller than the front spatter because the spatter travels in the direction of the bullet.