CTE Forensics/Law & Public Safety 1-2

1. CTE Forensics/Law & Public Safety1-2 Unit 4: Serology Blood Spatter Pattern Analysis

2. Learning Standards and Ojectives • CTE: 6.0 = Analyze investigative procedures (6.2 - 6.7); Science: Strand 1 - Concept 1 PO 1-4, Concept 2 PO 1-5, Concept 4 PO 1-4; Strand 5 - Concept 1 PO 1,2 & 4, Concept 2 PO 2 - 4, 6-7, & 11. • Students will be able To: • interpret the various aspect of blood patterns in the forensic investigation. • Measurements: : Quizzes, class discussions, comprehension assessments, performance assessments (labs).

3. Learning Objectives • List A-B-O antigens and antibodies found in the blood for each of the four bold types: A; B; AB; O • Understand & describe how whole blood is typed. • List & describe forensic tests used to characterize a stain as blood. • Understand the concept of antigens-antibody interactions & how it is applied to species identification & drug identification. • Contrast chromosomes & genes • Learn how the Punnett square is used to determine the genotypes & phenotypes of offspring. • List the laboratory tests necessary to characterize seminal stains. • Explain how suspect blood & semen stains are properly preserved for laboratory examination. • Describe that proper collection of physical evidence in a rape investigation.

4. Key Terms – Be prepared to take a Quiz • Acid Phosphates Hemoglobin X chromosome • Agglutination Heterozygous Y chromosome • Allele Hemozygous Zygote • Antibody Hybridoma cells • Antigen Locus • Antiserum Luminol/monoclonal antibodies • Aspermia Oligospermia • Chromosome Phenotype • DNA Plasma • Egg Polyclonal antibodies • Enzyme Precipitin • Erythrocyte Serology • Gene Serum • Genotype Sperm

5. Bloodstain Science Forensic Science Lab Activity Warning: Some material in this presentation and related videos may be too graphic for some people. T. Trimpe 2006 http://sciencespot.net/

6. What does the abbreviation BPA represent? What can an investigator learn from the analysis of a blood spatter?  Type and velocity of weapon  Number of blows  Handedness of assailant (right or left-handed)  Position and movements of the victim and assailant during and after the attack  Which wounds were inflicted first  Type of injuries  How long ago the crime was committed  Whether death was immediate or delayed Source: http://science.howstuffworks.com/bloodstain-pattern-analysis1.htm How does a blood droplet form? Click the image for an animation. http://www.crimescenetwo.com/img/popup/book2p2.jpg

7. How is blood evidence detected at a crime scene? Light Source Investigators will first examine the crime scene to look for areas that may contain blood. They may use a high-intensity light or UV lights to help them find traces of blood as well as other bodily fluids that are not visible under normal lighting conditions. • Blood Reagent Tests • These tests, referred to as presumptive tests, are used to detect blood at crime scenes based upon the properties of hemoglobin in the blood. Further tests at the crime lab can determine if it is human blood or not. • Examples: • Phenolphthalein is a chemical that is still utilized today and is usually referred to as the Kastle-Meyer test and produces a pink color when it reacts with hemoglobin. • HemaStix is a strip that has been coated with tetramethylbenzidine (TMB) and will produce a green or blue-green color with the presence of hemoglobin. Kastle-Meyer Test Video HemaStix

8. Luminol Reaction Luminol This chemical is used by crime scene investigators to locate traces of blood, even if it has been cleaned or removed. Investigators spray a luminol solution is throughout the area under investigation and look for reactions with the iron present in blood, which causes a blueluminescence. One problem is that other substances also react, such as some metals, paints, cleaning products, and plant materials. Another problem is that the chemical reaction can destroy other evidence in the crime scene. Fluorescein This chemical is also capable of detecting latent or old blood, similar to luminol. It is ideal for fine stains or smears found throughout a crime scene. After the solution has been sprayed onto the substance or area suspected to contain blood, a UV light and goggles are used to detect any illuminated areas, which appear greenish-white if blood is present. It may also react to many of the same things as luminol (copper and bleach). Fluorescein Reaction in UV Light LCV or Leuco Crystal Violet, is one type of chemical process that is used for blood enhancement. Using this test helps to make the blood evidence more visible so it can be photographed and analyzed.

9. Bloodstain Pattern Analysis Terms Satellite Spatters Spines Parent Drop • Spatter – Bloodstains created from the application of force to the area where the blood originated. • Origin/Source – The place from where the blood spatter came from or originated. • Angle of Impact – The angle at which a blood droplet strikes a surface. • Parent Drop – The droplet from which a satellite spatter originates. • Satellite Spatters – Small drops of blood that break of from the parent spatter when the blood droplet hits a surface. • Spines – The pointed edges of a stain that radiate out from the spatter; can help determine the direction from which the blood traveled.

10. Types of Bloodstain Patterns • Projected Bloodstains • Patterns that occur when a force is applied to the source of the blood • Includes low, medium, or high impact spatters, cast-off, arterial spurting, expiratory blood blown out of the nose, mouth, or wound. • Transfer or Contact Bloodstains • These patterns are created when a wet, bloody object comes in contact with a target surface; may be used to identify an object or body part. • A wipe pattern is created from an object moving through a bloodstain, while a swipe pattern is created from an object leaving a bloodstain. Blood Spatter Movie • Passive Bloodstains • Patterns created from the force of gravity • Drop, series of drops, flow patterns, blood pools, etc. Images from http://www.bloodspatter.com/BPATutorial.htm

11. History General Bloodstain Features • Bloodstain patterns deposited on floors, walls, bedding, and other relevant objects can provide valuable insights into events that occurred during the commission of a violent crime. • The crime scene investigator must remember that the location, distribution, and appearance of bloodstains and spatters may be useful for interpreting and reconstructing the events that produced the bleeding. http://youtu.be/H3F2fEGBgAQ

12. General Bloodstain Features Bloodstain pattern interpretation may uncover: • The direction from which blood originated • The angle at which a blood droplet struck a surface • The location or position of a victim at the time a bloody wound was inflicted • The movement of a bleeding individual at the crime scene • The approximate number of blows that struck a bleeding victim • The approximate location of an individual delivering blows that produced a bloodstain pattern • http://youtu.be/zjfdpenl1Rc

13. Effects of Surface Texture • Surface texture and the stain’s shape, size, and location must be considered when determining a bloodstain’s direction, dropping distance, and angle of impact. • Surface texture is of paramount importance. In general, the harder and less porous the surface, the less spatter results. • http://youtu.be/hYEWQsnMBzs

14. Directionality and Angle of Impact • The direction of travel of blood striking an object may be discerned because the pointed end of a bloodstain always faces its direction of travel. • The impact angle of blood on a flat surface can be determined by measuring the degree of circular distortion. At right angles the blood drop is circular; as the angle decreases, the stain becomes elongated (Ellipse) • http://youtu.be/M1TzSkrS2YM • Mathematically, the angle of impact can be calculated by the equation and determining the inverse of Sine A: Width of blood stain Sin A = ------------------------------ Length of blood stain

15. http://youtu.be/3jFKZaSeNjg

16. Impact Bloodstain Spatter Patterns • Impact spatter occurs when an object impacts a source of blood. • Forward spatter is projected outward and away from the source. • Back spatter, also known as blow-back spatter, is projected backward from the source.

17. Classifying Impact Spatter Using droplet size to classify impact patterns by velocity gives investigators insight into the general nature of a crime but cannot illuminate the specific events that produced the spatter pattern. http://youtu.be/gK1s3FCkOm8 http://youtu.be/J40wqqg_8Ww http://youtu.be/jzUhhOgK62g http://youtu.be/NBYz-TrsOlc http://youtu.be/gwBQ9n9dGTY • Low Velocity Spatter: drops with diameters of 4 mm or more normally produced by an applied force of up to 5 ft../sec. • Medium Velocity Spatter: drops with diameters from 1-4 mm with an applied force of 5 to 25 ft../sec. • High Velocity Spatter: drops with diameters of less than 1mm from an applied force of 100 ft./sec or faster.

18. Classifying Impact Spatter • The classifications of impact spatter as low, medium, and high velocity cannot illuminate the specific events that produced the stain size pattern. • In general, one should use stain size categories very cautiously and for descriptive purposes only in evaluating impact spatter patterns. • http://youtu.be/2UV_moaF45I

19. Area of Convergence • The area of convergence is the point on a two-dimensional plane from which the drops in an impact pattern originated. • This can be established by drawing straight lines through the long axis of several individual bloodstains, following the line of their tails.

21. Area of Origin • The area of origin of an impact bloodstain pattern is the area in a three-dimensional space from which the blood was projected. • This will show the position of the victim or suspect in space when the stain-producing event took place. • The string method is commonly used at a crime scene to approximate the position of the area of origin using found angles of impact of individual stains in the pattern.

22. Gunshot Spatter • Gunshot spatter is fine forward spatter from an exit wound and back spatter from an entrance wound. However, the gunshot produces only back spatter if the bullet does not exit the body. • Depending upon the distance from the victim that the gun was discharged, some back spatter may strike the gunman and enter the gun muzzle. This is called the drawback effect.

24. Cast-off Spatter • A cast-off pattern is created when a blood-covered object flings blood in an arc onto a nearby surface. • This kind of pattern commonly produced by a bloody fist or weapon between delivering blows. • The features of the cast-off pattern are affected by the size of the object, the amount of blood, and the direction the object was moving. • By counting and pairing forward/backward patterns, one may determine the minimum number of blows delivered. • http://youtu.be/UoXfHUm0h1o

26. Arterial Spray Spatter • Arterial spray spatter is caused by an injury to the heart or a main artery and the pressure of the continuing pumping. • The site of the initial injury to the artery can be found where the pattern begins with the biggest spurt. The trail away from this point shows the victim’s movement. • The oxygenated blood spurting from the artery tends to be a brighter red color than blood expelled from impact wounds.

28. Expirated Blood Patterns • An expirated blood pattern is created by blood that is expelled from the mouth or nose from an internal injury. • The presence of bubbles of oxygen in the drying drops or a lighter color as a result of dilution by saliva can differentiate a pattern created by expirated blood. • The presence of expirated blood gives an important clue as to the injuries suffered and the events that took place at a crime scene.

29. Void Patterns • A void is created when an object blocks the deposition of blood spatter onto a target surface or object and the spatter is deposited onto the object or person instead. • The blank space on the surface or object may give a clue as to the size and shape of the missing object or person. • Voids may be applicable for establishing the body position of the victim or assailant at the time of the incident.

30. Contact/Transfer Patterns • A contact or transfer pattern is created when an object with blood on it touches one that does not have blood on it. • Simple transfer patterns are produced when the object makes contact with the surface and is removed without any movement of the object. • The size and general shape of the object may be seen in a simple transfer. • Other transfers may be caused by movement of the bloody object across a surface.

31. Flows • Flow patterns are made by drops or large amounts of blood flowing by the pull of gravity. • The flow direction may show movements of objects or bodies while the flow was still in progress or after the blood dried. • Interruption of a flow pattern may indicate the sequence and passage of time between the flow and its interruption.

32. Pools • A pool of blood occurs when blood collects in a level (not sloped) and undisturbed place. Blood that pools on an absorbent surface may be absorbed throughout the surface and diffuse, creating a pattern larger than the original pool. • Considering the drying time of a blood pool can yield information about the timing of events that accompanied the incident.

33. Skeletonization • The phenomenon of skeletonization occurs when the edges of a stain dry to the surface. • This usually occurs within 50 seconds of deposition of droplets, and longer for larger volumes of blood. • After this time, if the bloodstain is altered by a contact of wiping motion, the skeletonized perimeter will be left intact. • Knowing the skeletonization time, an investigator determine the timing of movement or activity.

34. Drop Trail Patterns • A drop trail pattern is a series of drops that are separate from other patterns, formed by blood dripping off an object or injury. • The stains form a kind of line or path usually made by the suspect after injuring or killing the victim or injuring themselves. • The pattern may show direction and speed of movement, lead to a discarded weapon, or provide identification of the suspect by his or her own blood.

35. Documenting Bloodstain Evidence • Investigators should note, study, and photograph each pattern and drop to accurately record the location of specific patterns and to distinguish the stains from which laboratory samples were taken. • Two techniques used to document bloodstain patterns are: • Grid method: a grid of squares of known dimensions are set up over the entire pattern. • Perimeter ruler method: a rectangular border of rulers is set up around each pattern and a smaller ruler next to each stain.

36. Interpreting Bloodstain Evidence • Some jurisdictions have a specialist on staff who will decipher patterns either at the scene or from photographs at the lab. • However, it is important that all personnel be familiar with patterns to properly record and document them for use in reconstruction. 45 minute video http://youtu.be/7xWgqafAFMM

37. Blood Spatter Labs • You will be creating sample drop patterns using single drops and multiple drops. We will also investigate the effect of motion and the angle of impact on blood spatter. • This can be messy! Be very careful to keep the blood on the paper and not on yourself, the table, or floor. • Hold you hand as steady as possible when making the drops. Brace your wrist against the meter stick to help you. • Get your materials from your teacher – paper, black marker, meter stick, goggles, and a bottle of blood. If you make a mess, clean it up immediately!

38. Lab 1: Single Droplets • Label two large pieces of construction paper as shown below. Single Drops Group Members Single Drops Group Members Keep your drops in the correct area of the paper. 25 50 75 100 • To do the lab, put on your goggles and hold the dropper bottle upside down so that the end of it is 25 cm from the paper. GENTLY squeeze the bottle so that ONE drop of blood is released and lands in the correct location on your paper. It should NOT hit the meter stick. • Repeat TWO more times at this height for a total of three drops. • Continue making drops of blood on your paper, but put the drop in a different area of the paper and change the height each time. • When you are done, analyze your results and answer the questions on your worksheet. Make a mistake? Use a paper towel to wipe it off your paper!

39. Lab 1 Questions Use your results to answer these questions. What did you notice about the diameter of the parent droplets as you increased the height of the drop? How do the spines compare from the different heights?

40. Lab 2: Multiple Droplets • Label a long piece of butcher paper (2 -3 meters in length) as shown below. Multiple Drops Group Members Keep your drops in the correct area of the paper. 25 50 75 100 • To do the lab, put on your goggles and hold the dropper bottle upside down so that the end of it is 25 cm from the paper. GENTLY squeeze the bottle so that ONE drop of blood is released and lands in the correct location on your paper. The drop should NOT hit the meter stick. • Without moving your hand, release ONE more drop onto the first drop at that height. If you make a mistake, wipe it off with a paper towel and try it again. • Continue making drops of blood on your paper so you have three sets for each height. • When you are done, analyze your results and answer the questions on your worksheet. Clean up your area and put away your materials before you leave class.

41. Lab 2 Questions Use your results to answer these questions. What happened when one drop landed on top of another one? What did you notice about the diameter of the parent droplets as you increased the height of the drop? What do you notice about the diameter of the satellite spatter as you increased the height of the drop?

42. Lab 3: Motion Droplets Walking Direction • During this lab, you will see how motion affects the size and shape of the droplets and spines. You will need a long piece of butcher paper (4-5 meters in length) and tape to secure it to the floor. You will also need safety goggles. • To do the lab, you will need to hold the dropper bottle upside down so that your hand is out and away from your body (waist level), but is still over the paper. • Start off walking at a SLOW WALKING RATE along the paper strip from one end to the other and GENTLY squeeze the bottle as you walk so that blood is released ONE DROP at a time. Be sure that all the drops land on your paper strip. • Repeat this procedure using a NORMAL WALKING RATE and a FAST WALKING RATE. Miss the paper? Use a paper towel to wipe it off the floor! • When you are done, analyze your results and answer the questions on your worksheet. Clean up your area and put away your materials before you leave class.

43. Lab 3 Questions Use your results to answer these questions. Draw a sketch of the droplets showing the size, shape, and/or distance between them at each speed in the chart below. What did you notice about the shape of the droplets as you increased your walking speed? What did you notice about the spines as you increased your walking speed? What did you notice about the distance between the droplets as you increased your walking speed?

44. Lab 4: Angle of Impact Clipboard & Paper Angle Guide • You will be creating sample drop patterns created by droplets landing at different angles from the same height. • Label five pieces of copy paper with your names and then indicate the angle for each droplet - 15o, 30o, 45o, 60o, or 75o. • Place the first piece of paper on the clip board and align the clipboard with the 15o line. Hold the bottle of blood at a height of 50 centimeters from the top of the table. • GENTLY squeeze the bottle so that ONE drop of blood is released and lands on the paper. Repeat two more times at this angle. • Continue testing by dropping blood from a height of 50 centimeters at each of the other angles. Height of50 cm • When you are done, answer the questions on your worksheet. Clean up your area and put away your materials before you leave class.

45. Lab 4 Questions Use your results to answer the question. What did you notice about the shape of the droplets as you increased the angle of the paper?

46. Which of the three blood droplets shown would have been created by a wound in the lower part of the leg? Explain. If you have a blood droplet as shown at left, what does it tell you? Explain. Quick Review If you find a trail of blood with droplets that are round and close together, what could this mean?