Bloodstain Pattern Analysis

 

 

Bloodstain Pattern Analysis

"It will have blood, they say; blood will have blood" -William Shakespeare, Macbeth

    

 

 

• Section 1a. Vocabulary: 

 

platelets	spatter	back spatter	area of convergence	exit wound	void	drip trail pattern
bloodstain	satellite spatter	low-velocity spatter	area of origin	cast off	transfer pattern	grid method
droplet	angle of impact	medium-velocity spatter	string method	arterial spray	flow pattern	perimeter rule method
forward spatter	impact spatter	high-velocity spatter	entrance wound	expirated blood pattern	skeletonization	erythrocytes
leukocytes	hemoglobin	luminol	precipitin

 

 

• Section 1b. Mastery Objectives and Critical Skills: 
• Identify blood at the crime scene
• Process blood samples from the crime scene (type, DNA, etc)
• Categorize the blood spatter patterns as satellite spatter, impact spatter, forward spatter, back spatter, low-velocity spatter, medium-velocity spatter, high-velocity spatter, expirated blood pattern, transfer pattern, flow pattern, drip trail pattern and skeletonization 
• Identify the 12 categories of patterns
• Describe the 3 methods for identifying blood at a crime scene
• Discuss the 3 types of information one gets from blood at a crime scene 

 

• Section 2a. Required Readings covered on Tests and Quizzes: 
• Richard Saferstein Forensic Science 2011 pages 376-401, 293-297, 303- top of 304, 
• http://science.howstuffworks.com/csi.htm 
• http://www.crime-scene-investigator.net/blood.html 

 

• Section 3 – Anticipated In Class Activities: 
• Vertical Drip Patterns Lab
• different colored dyed blood in different patterns (silver, red) 
•  Smithsonian Channel: Catching Killers- Blood Spatter Season 2 Episode 4 http://www.smithsonianchannel.com/sc/web/series/1003122/catching-killers/3375551/blood-spatter (Need account? Ask Dr. G) 
• http://www.youtube.com/watch?v=J40wqqg_8Ww Dexter Explains Blood Spatter 
• Watch a Dexter Episode of choice (Netflix) 
• Connect the Dots Activity 
• recreate a dexter crime scene and have kids try to figure out how the victim was killed based on the patterns (in blood)  

 

• Section 4 – Outside Class Assignments: 

1. Concept Maps 
1.  droplet, platelets, leukocytes, erythrocytes, spatter, satellite spatter, angle of impact, bloodstain
2. bloodstain pattern, impact spatter, forward spatter, back spatter, low velocity spatter, medium-velocity spatter, high-velocity spatter, low-velocity spatter
3. area of convergence, area or origin, string method, entrance wound, exit wound, cast-off, arterial spray
4. expirated blood pattern, void, flow patterns, skeletonization, transfer pattern, drip trail pattern, grid method, perimeter rule method

 

     2.  What characteristics of the criminal can be identified from the blood found at the scene? Age, gender and DNA.

 

     3a. What are the three types of analyses used to process blood in a lab? Conventional Serological Analysis, Restriction Fragment Length      Polymorphism (RFLP), and Polymerase Chain Reaction (PCR). 

 

     3b. How are they defined? Conventional Serological: Analysis of the proteins, enzymes, and antigens present in the blood.

     RFLP: Direct analysis of certain DNA sequences present in the white blood cells. 

     PCR: Analysis of certain DNA sequences that have been copied multiple times to a detectable level 

 

     4. Match the terms of the blood spatter with the image that corresponds with it. 

Name of Pattern	Picture (a, b, f, i, l) copyright FORident Software: http://hemospat.com/bloodstain-pattern-analysis-terminology
1. satellite spatter	a.
2. high-velocity spatter	b.
3. back spatter	c.
4. skeletonization	d.
5. flow pattern	e.
6. impact spatter	f.
7. drip trail pattern	g.
8. low-velocity spatter	h.
9. void pattern	i.
10. transfer pattern	j.
11. forward spatter	k.
12. expirated blood pattern	l.
13. medium-velocity spatter	m.

(Answers: 1f, 2e, 3h, 4g, 5i, 6c, 7k, 8d, 9l, 10b, 11m, 12a, 13j) 

  

     5. What are the 3 methods for identifying blood at the crime scene? Luminol Tests, Hydrogen Peroxide and Hydroxide.

 

     6. What are the three types of information one might get from a crime scene? Height, location and handedness. 

 

• Section 5 – Outside Class Activities and Bonus Points: You may want to include some “stretch” activities that a student who is really excited about the topic can pursue.  Have them visit a place, build a collections, research a related topic.