Blood separation

This page is about how blood separates.

Background information

Blood is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume) Source : Wikipedia

“If a test tube of blood is left to stand for half an hour, the blood separates into three layers as the denser components sink to the bottom of the tube and fluid remains at the top.” Source: ncbi.nlm.nih.gov

“The fibrin threads form a mesh that traps platelets, blood cells, and plasma. Within minutes, the fibrin meshwork begins to contract, squeezing out its fluid contents. This process, called clot retraction, is the final step in coagulation.” Source: britannica.com on coagulation of blood.

“Subsequently, the blood clot begins to retract causing a separation of the remaining liquid portion that is referred to as serum (Figure 2). Source: iabpa article, page 4.

“Within a few minutes after it leaves the body, blood can begin the clotting mechanism. As the clots form the blood begins to retract from the edges of the pool, leaving the yellowish serum at the periphery. In some cases the time of pooling can be estimated due to the degree of serum separation.” Source: www.forensic-lab.com page on blood evidence.

The David Camm case

These photos show the scene at a triple-homicide ( the family of David Camm were murdered by Charles Boney ). The serum has flowed across the garage floor. Note that Rob Stites, an expert with very questionable credentials, did not understand what happened, the probable cause claimed “The cleaning substance was thrown over the back deck of the above mentioned house also leaving a trail from the garage area” (see page 18 here ).

Photos of blood pools

These photos show pools of blood, with serum apparently flowing away from the pools:

bathmatandbloodpool

The serum has flowed away towards the black bathroom scales top right.

HallFromBathroom

The serum appears to have flowed towards the linen cupboard entrance.

SinksAndLinenCupboard

View into the linen cupboard. The cardboard box has a brown stain, possibly from serum flowing into the cupboard.

The same photo cropped:

SinksAndLinenCupboardCropped

Discussion

Flores wrote in his investigation report:

“Some of the blood appeared deluded[sic] as though water had been spilled on it for a short period of time, while other sections of the blood spatter appeared to resemble heavy arterial spurting.”

and

“There were areas with large thick puddles of dried blood all over the floor with a combination of light deluded[sic] areas throughout the majority of the floor. A closer look at a cardboard box in the linen closet next to the sink revealed a reddish color watermark a few inches up from the floor. This indicated to me that the floor, at some time after the incident, had a large amounts of water on it.”

Could it be he mistook the water from the blood plasma for water coming from the shower or sinks?