I find it absolutely fascinating how bloodstain patterns are interpreted and examined to help solve a crime. This can answer so many questions on where the perpetrator was standing, how tall the perpetrator was, weapon used, and how the crime was committed. Once you get past the “blood” part and really take an objective look at the patterns, it reveals a whole new perspective of what had transpired during the crime.
The importance of blood spatter evidence can’t be overestimated. Notes and sketches always supplement the photographs of bloodstains. It is noted the detailed description of the physical characteristics of the blood patterns, such as size, location, shape, distribution, and physical features. There are other notations made on the actual color of the blood, reddish-brown or bloodlike. Further, the blood is then classified into categories similar to how fingerprints get classified.
There has been a new methodical technique for documenting bloodstain pattern as part of the crime scene analysis. This technique allows for the complete documentation of bloodstain patterns. It is essentially photo roadmap that tells the story. Toby L. Wolson of the Miami-Dade Police Department’s Crime Laboratory developed the roadmapping technique.
To properly document the bloodstain pattern roadmap:
1. Identify the patterns you want to document and photograph the patterns just as they appear.
2. Use yellow scales with tape or glue so that they surround the blood pattern both vertically and horizontally.
3. Label each separate blood pattern with an adhesive mapping symbol, such as A, B, C, etc.
4. Find the most important individual stains within each pattern and label with an adhesive scale, showing the impact pattern, directionality, and area of convergence.
5. You are ready to take your overall, medium distance, and close up photographs.
“All objects in the universe are unique.”
I love this quote from Nickel & Fisher in their book Crime Science: Methods of Forensic Detection. I think it definitely speaks for the roadmap of bloodstain pattern evidence.
“No two things that happen by chance ever happen in exactly the same way. No two things are ever constructed or manufactured in exactly the same way. No two things wear in exactly the same way. No two things ever break in exactly the same way.”
Crime Watch Blog: www.emilystonecrimewatch.wordpress.com/
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Books: Compulsion = Dead Game = Silent Partner = Screenwriting