DOCUMENTING BLOODSTAINS AT THE SCENE
Presumptive serological tests can be employed to discover if the stain in question is truly blood; if it’s tomato sauce, then it’s probably not worth the analyst’s time. Additionally, many of the enhancement techniques used for visualizing blood discussed earlier in this chapter can be used to visualize bloodstain patterns. The documentation of bloodstains is painstaking work but crucial to a successful reconstruction. Tom Bevel and Ross Gardner , two well-known bloodstain pattern analysts, recommend the following photographic guidelines:
• Document the entire scene as discovered, including “establishing” photographs.
• Photograph pattern transfers, pools, and other fragile patterns first.
• Document patterns with “establishing” photographs that show the pattern’s relationship to landmarks or other items of evidence.
• Take macro and close-up photographs; include a scale in every photograph.
• When reconstructing point-of-origin, document individual stains used in the reconstruction.
Note-taking, sketching, and measurements must accompany photographic docu mentation to help organize and describe the stains at the scene.
FIGURE 1 Computer software can assist in the reconstruction of bloodstain patterns by automatically calculating angles and vectors.
