1. Image from: http://science.howstuffworks.com/environmental/life/human-biology/blood.htm

2. Blood collection  Package in NON-air tight container, such as a paper bag, so that no mold grows— dry blood can still be analyzed

3. Blood analysis  Step 1: Use chemicals to determine if the substance found is blood  Examples 1. Hematest—Hemastix test strip turns blue due to detection of hemoglobin by-products 2. Luminol Test—detects dried or washed blood (spray suspected area and if blood is present, it will glow in the dark)

4. Blood analysis  Step 2: Is it human blood?  Determine using....  karyotype  Precipitin Test 1. = the more standard and quick method 2. very sensitive and accurate test 3. a serum is added to the crime scene sample... if it is human blood, it will clump as a reaction

5. Blood analysis  Step 3: If human, then analyze it further a. Blood type  A, B, and O blood types based on antigens on surface of red blood cells  PhenotypesGenotypes AI A I A, I A i BI B I B, I B i ABI A I B Oii  NOTE: A and B are codominant to each other, but both A and B are dominant over O b. DNA fingerprint, etc. (see DNA notes)

6. Properties of Human Blood  Circulates throughout body to transport oxygen, electrolytes, nourishment, hormones, vitamins, and antibodies to tissues an organs  Contains red blood cells (erythrocytes), white blood cells (leukocytes), plasma, and platelets  Held together by STRONG cohesive forces Image from: http://www.webmd.com/heart/anatomy-picture-of-blood

7. Blood...  Does NOT fall in tear drop form (spherical)  Will not break apart as it falls through air  Is 6 times more viscous than water  Has average volume of 0.05 ml (diameter = 4.56 mm)  Blood hitting surface  --hard smooth surface = creates little spatter  --wood or concrete = create larger spatter  Spattered blood = random distribution of bloodstains Images from: http://www.clt.uwa.edu.au/__data/page/112508/fsb05.pdf

8. Significance of SPATTERED blood...  Allows for determination of area or location of origin of blood source (triangulation)  Place someone at a crime (on clothing)  May determine mechanism that created pattern (including speed of drop at impact, weapon used, direction of travel, angle of impact,) Image from: http://science.howstuffworks.com/bloodstain-pattern-analysis3.htm

10. Look for Convergence

11. Real Crime Scene

12. Get Computer Help (Software is available!)

13. Size, Shape, and Directionality (deals with “flight” of bloodstain) Images from: http://www.crimescene-forensics.com/Blood_Stains.html and http://science.howstuffworks.com/bloodstain-pattern-analysis3.htm  Direction of travel --Narrow end of elongated bloodstain points in direction of travel (impact angle < 90 degrees) Picture: --Circular bloodstain = no travel, dropped @ 90 degree angle Picture:

14.  Rule of Thumb: As impact angle goes down, bloodstain shape becomes more elongated.

15. Size, Shape, and Directionality (deals with “flight” of bloodstain)  Impact Angle calculation (for elliptical bloodstains)  1 st find ratio of width to length (see picture)  Then take the arc sin of that ratio  Thus...  Angle of impact = sin -1 (width/length)

16. sin θ = W / L W L What does W = L mean? sin θ = 1 → θ = 90  Drop is a circle!

17. Classify spatters (3):  LVIS— low velocity impact  Force = up to 5ft/sec  diameter= 4 mm+  Examples: blood falling from an open wound Images from: http://www.crimescene-forensics.com/Blood_Stains.html and http://science.howstuffworks.com/bloodstain-pattern-analysis1.htm  LVIS increase in size as the distance fallen increases, however, the size of the spatters will remain constant after approx 4 feet

18.  MVIS—medium velocity impact  Force = 5-25 ft/sec  diameter = 1-3 mm  Examples: blood flicked off finger and blunt object used on victim Image from: http://www.crimescene-forensics.com/Blood_Stains.html

19.  HVIS—high velocity impact  Force = +100 ft/sec  Diameter = < 1mm  Mist-like appearance  Examples: gunshots, explosion, high speed collisions “It is important to note that the term "Velocity" does not measure the speed at which the blood is traveling, but rather is used to describe or measure amount of force applied to the blood, to cause it to spatter.” ~http://www.crimescene-forensics.com/Blood_Stains.html

20. Weapon used...  Impact spatters: 1-Gunshot—mistlike pattern (<1mm blood spots) --Size range dependent on amount of blood, caliber of weapon, # of shots and location on body, hair/clothes --blowback or back spatter possible 2-Beating or stabbing—sizes 1-3 mm --depends on force and quantity of blood --only exposed blood makes spatter (not1 st blow) --type of weapon influences pattern

21. Other Bloodstain patterns  Satellite or secondary spatter = single drops, circular or oval, 0.1=1 mm size  Drip pattern = multiple, free falling drops on horizontal surface  Castoff pattern = multiple blows to same area where wound has occurred and blood has accumulated

22. Other Bloodstain patterns  Expirated patterns = blood that has pooled in lungs, sinuses, or airway passages is expelled from body  Arterial patterns = breaching of artery and result is gushing or spurts of blood  Blood transfer pattern = blood stained object contacts unstained object (can be a smear)  Dried blood = color changes... red –to— reddish brown —to— black

23. Void Image from: http://hemospat.com/terminology/index.php?org=SWGSTAIN&term=void

24. Drip Pattern Image from: http://hemospat.com/terminology/index.php?org=SWGSTAIN&term=void

25. Expiration Pattern Image from: http://hemospat.com/terminology/index.php?org=SWGSTAIN&term=void

26. Transfer Pattern Image from: http://hemospat.com/terminology/index.php?org=SWGSTAIN&term=void

27. Documentation of Bloodstain  Document size, shape, and distribution of stains and patterns  Use photographs, video, diagrams, and notes  Collect articles of evidence with significant or questionable patterns (Remember Luminol can be used to detect or enhance bloodstain patterns) Image from: http://science.howstuffworks.com/luminol1.htm