Drying Stages of Blood Drops

Abstract

Blood is one of the most important & most frequently encountered evidence in criminal investigation. It can be found in almost every type of criminal activity involving physical violence like murders, robberies, rape cases, etc. Blood stain may found on location such as seen of occurrence, the culprit, the victim, the weapon, of offence, the vehicle and the route taken by the culprit. The position, size & shape of the stain often help in reconstruction of crime seen. The stain may be in the form of splashes, smears, & pools. The colour of the bloodstains varies accordingly to their age, the amount of blood present, and the nature of the material. As bloodstain increases in age, they progress through series of colour changes from red to reddish brown to green & eventually to dark brown to black. When blood is exposed to an external environment the drying process on various surfaces is initiate. Size, volume, nature of target surface, & influence of external environment such as temperature humidity, air flow affects the drying time of bloodstain. The drying of bloodstain is initially around the edges or periphery and proceeds inward to the central portion of the stain as the drying process continues. Drying time and skeletonization are both important alteration of blood. Presence of significant dried & clotted blood on surface at a scene indicates a significant time lapse between blood shade & the observation of the blood.