NCJ Number
194652
Journal
Canadian Society of Forensic Science Journal Volume: 34 Issue: 4 Dated: December 2001 Pages: 209-214
Date Published
December 2001
Length
6 pages
Annotation
This study examined the effect of the target surface on the clotting times of human blood and the difference between the clotting times for various individuals and various surfaces, which will serve as guidelines in evaluating clotted blood at crime scenes.
Abstract
To determine the clotting times for human blood between individuals and with the substrate upon which the blood was deposited, an experiment was conducted where human blood was collected from laboratory volunteers in 10 mL red top blood tubes containing no preservatives or anti-coagulants. In a larger volume study, blood was drawn into 15 mL tubes of blood. Clotting times were shown to vary between individuals and with the substrate on which the blood was deposited. Serum was observed to temporarily separate from the flowing blood deposited on concrete for two of three samples. It was recommended that an in-depth study on serum separation be conducted in the area of bloodstain pattern analysis. It was noted that temperature, humidity, and other conditions and circumstances would have an effect on the clotting times, as well as the medical condition and medications of the individual bleeding. Tables