String is run from points at which blood droplets impact to a precalculated directional angle converging at the area of origin. The string method, however, is often time-consuming, especially if the crime scene contains many blood droplets and strike patterns. In addition, two persons are generally needed to process the bloodstain evidence. One person is needed to hold one end of the string at the blood droplet's point of impact, while a second person is needed to extend the other end of the string to the area of origin. The tool used most frequently in crime scene investigation and evidence analysis to manually measure blood droplet impact angles is the standard protractor. When the nature of a criminal investigation demands that impact angles be precisely measured and that area of origin be accurately reconstructed, the use of a protractor with the capability to measure angles in three-dimensional space is preferred. 3 references, 1 table, 5 figures.