Assessment of clotting factor deterioration as a forensic indicator of time since bloodshed

Taela L Luckins

Blood is the only fluid connective tissue within the human body, which is important for maintaining life, but can also play a key role in the event of death. The soluble protein component of blood includes clotting factors that are crucial to maintaining the physiological process of haemostasis. This process is the mechanism that leads to the formation of a blood clot in the event of vascular injury to minimise as much possible blood loss. Alongside the formation of clots, haemostasis also works to maintain blood fluidity proceeding a clotting event through another physiological mechanism called fibrinolysis, the breakdown of the blood clots. The process can be split into primary and secondary haemostasis, with the soluble clotting factors being involved in secondary haemostasis in a process called coagulation. Primary haemostasis works to form a weak platelet plug, whilst secondary haemostasis forms a stabilised blood clot by producing a fibrin mesh to secure it in place for the duration of injury healing. Simultaneously, fibrinolysis begins the dissolution of the blood clot to maintain blood fluidity. In the field of forensics, blood has many applications to criminal proceedings through different forms of evidence. Aside from bloodstain pattern analysis (BPA) which used blood shapes to interpret deposition, forensic analyses of blood focus mainly on the white and red blood cells present within blood and are unable to determine how long blood has been present at a crime scene. Determining the age of bloodstains may provide important evidence in many situations, particularly cases where an alibi must be proven, by acting as a reference point for the time at which a crime had occurred for event reconstruction purposes, in combination with other evidence including witness statements and personal testimonies. To develop a novel technique for bloodstain aging, this study assesses scholarly literature employing different methodologies for the age estimation of bloodstains. This area of forensics has been researched for over 80 years, yet no methodology has been worthy of inclusion into standard practice. Indeed, the haemostatic pathway, particularly the coagulation pathway, has not yet been explored as a biomarker target for a bloodstain aging method. In the event of a violent assault or homicide, blood is deposited on surfaces at crime scenes in various patterns and pools depending on the mechanism of injury. Where bloodshed is involved, it is not uncommon for crime scene responders at serious assaults or homicides to be met with still-wet blood pools. Blood clotting processes occur both inside the circulatory system as well as outside of the body and may be detectable in such scenarios. This literature review aimed to assess current methodologies to uncover gaps in the understanding of bloodstain aging in relation to various methodologies and to inform potential of biomarkers within haemostasis that may provide information on age estimation of bloodstains at crime scenes.

Assessment of clotting factor deterioration as a forensic indicator of time since bloodshed

Files and links (1)

Abstract

Details

Metrics