*A new formula helps CSIs determine whether a victim took a blow standing up.*

**1//** Height of the blood at the beginning of its parabolic arc, that is, when it left the body.

**2//** Tangent of the angle at which the first blood drop hit the ground.

**3//** Tangent of the angle at which the second drop hit the ground.

**4//** Horizontal distance the first drop traveled.

**5//** Horizontal distance the second drop traveled.