1. Bertino & Bertino Forensic Science: Fundamentals and Investigations, 3 rd ed. Visit: www.BertinoForensics.com Bertino & Bertino, Forensic Science: Fundamentals and Investigations, 3rd ed. © 2021 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part.

2. Blood Evidence: Tells a Story Direction from where the blood impacted Location of blood’s origin Distance of bloodstain from the source Speed of the blood Position of victim & perpetrator Number of potential perpetrators Movements after the blood was shed Personal Identification Bertino & Bertino, Forensic Science: Fundamentals and Investigations, 3rd ed. © 2021 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part.

3. Direction of Travel: “satellites or tails” 5 ml blood squirted from a syringe from height of 1 m Bertino & Bertino, Forensic Science: Fundamentals and Investigations, 3rd ed. © 2021 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part.

4. Area of Convergence 2-Dimensional Draw Lines of Convergence along middle of blood droplets Start from the “tail” or satellites, work to origin Draw smallest circle around intersecting lines Bertino & Bertino, Forensic Science: Fundamentals and Investigations, 3rd ed. © 2021 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part.

5. How to Measure Blood Droplets Measure width and length of each blood droplet Do NOT include any spines, tails or satellites Bertino & Bertino, Forensic Science: Fundamentals and Investigations, 3rd ed. © 2021 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part.

6. Area of Origin: Source Blood in 3-D Direction? Calculate angle of impact for 3 drops: W/L inverse sine Bertino & Bertino, Forensic Science: Fundamentals and Investigations, 3rd ed. © 2021 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. AREA of CONVERGENCE BERTINO

7. String Method: Area of Origin Use Three Paper Blood Drops: 1. Determine direction of blood 2. Estimate the area of convergence (string, tape) 3. For EACH droplet of blood: a. Calculate the angle of impact width/length and take the inverse sine b. Place origin protractor where blood first struck target 4. Use a protractor and string to show angle of impact Attach the string a. to floor in front of blood drop b. to pole (or person) c. area of origin: intersection strings Bertino & Bertino, Forensic Science: Fundamentals and Investigations, 3rd ed. © 2021 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part. BERTINO

8. 2 nd Degree Functions/Inverse Sine Bertino & Bertino, Forensic Science: Fundamentals and Investigations, 3rd ed. © 2021 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part.

9. Act 8-1: A Presumptive Test for Blood Act 8-2: Creating and Modeling Blood-Spatter Patterns Act 8-3: Blood-Spatter Analysis: Effect of Height on Blood Drops Act 8-4: Area of Convergence Act 8-5: Blood Droplet Impact Angle Act 8-6: Area of Origin Act 8-7: Crime-Scene Investigation Act 8-8 ACT: Antigen and Antibodies Activity Bertino & Bertino, Forensic Science: Fundamentals and Investigations, 3rd ed. © 2021 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible website, in whole or in part.

10. FOR MORE INFORMATION Refer to Chapter 8 of Forensic Science: Fundamentals and Investigations 3 rd ed. by Bertino & Bertino Visit: www.BertinoForensics.com