The Difference Between Preliminary Field and Laboratory Testing
[WLOs: 1, 2, 4] [CLOs: 2, 3, 4, 5]
Handling and processing evidence is an integral component of crime scene management because it lays the foundation for everything the court must consider when weighing the admissibility of evidence. For the most part, the courts prefer testing being carried out in a laboratory setting. However, there are exceptions, such as times when an initial examination also yields valuable information. In this assignment, you will differentiate between testing that might be done on-scene versus in the laboratory, identify testing that might be subject to preliminary testing, as well as compare the different results yielded by preliminary field versus laboratory testing. Support your assignment with examples from this week’s required material(s) and/or a minimum of three other scholarly or credible resources and properly cite any references.
Prior to beginning work on this assignment, please review the following:
- From the text:
- Chapter 8: Pattern Evidence 1: General Patterns and Fingerprints
- Chapter 9: Pattern Evidence 2: Firearms, Tool Marks and Document Analysis
- From the free, downloadable resource at the web page Crime Scene Investigation Guide (Links to an external site.):
- Section D – Completing and Recording the Crime Scene Investigation
- Section E – Crime Scene Equipment
- The articles:
- An Automated Approach to the Classification of Impact Spatter and Cast-Off Bloodstain Patterns (Links to an external site.)
- Chemical Enhancement of Footwear Impressions in Blood Recovered from Cotton using Alginate Casts (Links to an external site.)
- From the free PDF copy at the web page Strengthening Forensic Science in the United States: A Path Forward (2009) (Links to an external site.):
- Section 10. Automated Fingerprint Identification Systems
- Section 11. Homeland Security and Forensic Science
- The video Forensic Science: Analysis of Drugs Using Colour Tests (Links to an external site.) shown above
- From the video Bodies, Blood, and Ballistics: Forensics School, Part One (Links to an external site.):
- Segment 2. Forensics: Blood Spatter 02:35
- Segment 5. Blood Spatter and Trajectories 04:35
- From the video Hands-On Police Work: Forensics School, Part Two (Links to an external site.):
- Segment 3. Crime Scene Photography 02:27
- Segment 6. How to Capture and Record Fingerprints 03:10
- Segment 8. Crime Scene Documentation 03:18
You are also strongly encouraged to review the list of recommended resources, as they may assist you with this assignment.
In your paper, address the following:
- Identify what types of evidence might be subjected to preliminary or field testing.
- Describe at least two types of testing that might be done on scene.
- Differentiate between why some evidence can and should be subjected to preliminary testing on scene, while other types should not.
- Explain how the on-scene test compares to laboratory testing.
- Compare and contrast the results yielded by preliminary field versus laboratory testing.
- Compare and contrast the admissibility of on-scene versus laboratory testing at trial.
The Difference Between Preliminary Field and Laboratory Testing paper