When an object used to injure another person is swung multiple times with blood on it, it creates this pattern. Because of the blood on it, when it's swung it creates an arching pattern of blood that is left on the surfaces around the crime.

High Velocity Impact Stain(HVIS)

This is when a high velocity force, most commonly caused by a gunshot, impacts a blood source. The Spatter that results from this impact is very small and fine. This is because this type of impact usually is going around 100 feet per second.

Medium Velocity Impact Stain (MVIS)

This happens when a medium force impacts a blood source and cause a blood Spatter. The medium force is usually from a blunt object, when the person is hit the blood spatters travel around 5-100 feet per second causing a spray like pattern to appear once it stops

Low Velocity Impact Stain (LVIS)

This usually happens when blood drips. The blood is moving slower that 5 feet per second. Due to how slow its moving the blood that drops are larger in size.

Passive Drop

Drops of blood that come from gravity pulling it down. Whe. A person is bleeding and it drops Dow. From them onto the floor because of the force of gravity.

Swipe Pattern

When an object contains blood on it and is swiped onto a surface clear of blood. It creates a pattern from the movement and the direction can usually be determined from the feather feather edge of it.

Transfer/Contact Stain

This happens when an object is wet with blood and comes into contact with another object or surface. The print that is left behind is from the drenched object. As seen above, the bloody object was a shoe that left a partial pattern in the surface.