Flight Characteristics of Human Blood and Stain Patterns

In healthy adults, volume is from 4.5 to 6.0 liters;

not unlike other fluids, it will act in a predictable manner

when subjected to external forces.

            Target surface considerations: size, shape, directionality.

Falling through air from fingertip

it will be larger than a drop from hypodermic, smaller

than if from baseball bat.

            Viscosity is defined as resistance to change of form or flow.

The stain produced by freefall is a function of volume,

the texture it impacts; in order to create spatter tension must be disturbed,

surfaces ruptured.

                                    Size range is dependent on quantity, on caliber

            and impeding factors, such as hair, clothing, etc.

Elongated            a stain points in the direction of travel,

if found on the underside of table and chair

                                                                        he/she was on or near floor—

            (fist, bat, concrete block)

            the number of blows effects resulting pattern.

She is lying prone, lower body on linoleum floor, left arm flexed inward,

white pharmacy bag around wrist, she is wearing gold bracelets and a watch.

Figure 9.12 Impact spatter produced by beating mechanism.

Note: The text of the poem is collaged source material taken from Recognition of Bloodstain Patterns by Stuart H. James, Paul E. Kish, and T. Paulette Sutton

Blood, Ink, Patron of Thieves

The wound still weeps            ink and blood

            stamped into bed sheets, a circle divided
like arms outstretched

            like palms fixed in place with a nail.

Seal of Hermes                        messenger patron

its color lost, surface scarred
where needle cut
                                    a little too deep.

                        Machine, iron, to the uninitiated
            gun
                        click click crack

            what once was seashell tied to stick,
its ragged edge sharpened to teeth.