In crimes scenes where blood has been shed, valuable evidence can assist in solving the crime and prosecuting the suspects. This evidence includes latent and patent footwear impressions, bare sole impressions, and finger and palm impressions. In instances where a scene has been cleaned up, the use of specialized chemical processing techniques permits faint or non-visible blood evidence to be enhanced for optimal visualization. This can be further enhanced using Adobe Photoshop tools.
This Documentation and Chemical Enhancement of Bloody Crime Scenes course of instruction will focus on locating, documenting, and chemically processing bloodstained evidence. Examples that will be covered are latent and patent footwear impressions and friction ridge detail. The segment on footwear will include the required photographic techniques in order for a footwear examiner to make a comparison to a suspect’s shoe.
Sometimes blood is transferred to dark or multicolored clothing or other types of physical evidence making it difficult if not impossible to see. The student will be shown examples of methods that can be employed to visualize this evidence without the use of chemicals, using digital imaging enhancement techniques and Adobe Photoshop.
This course will also have a segment on the different types of bloodstain patterns encountered at a scene and the actions that may have caused them.
The following chemicals will be discussed and used by students:
Leuco Crystal Violet (LCV)
Photography is an integral part of documenting chemically enhanced bloodstains. Students should bring with them a digital SLR camera mounted with 50mm or macro lens, off shoe flash and tripod that will allow 90 degree photography of floor surfaces. It is highly recommended that the student have a working knowledge and understanding of basic photography including depth-of-field, shutter speed, apertures, and ISO relationships.