The Difference Between Preliminary Field and Laboratory Testing

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 GuideLinks 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 PatternsLinks to an external site.
  • Chemical Enhancement of Footwear Impressions in Blood Recovered from Cotton using Alginate CastsLinks 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 TestsLinks to an external site. shown above
• From the video Bodies, Blood, and Ballistics: Forensics School, Part OneLinks 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 TwoLinks 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 assignment, 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 assignment 

• Must be 750 words in length (not including title and references pages) and formatted according to APA StyleLinks to an external site. as outlined in the Writing Center’s APA Formatting for Microsoft WordLinks to an external site. resource.
• Must include a separate title page with the following:
  • Title of assignment
  • Student’s name
  • Course name and number
  • Instructor’s name
  • Name of the school
  • Date submitted
• Must utilize academic voice. See the Academic VoiceLinks to an external site. resource for additional guidance.
• Must include an introduction and conclusion paragraph. Your introduction paragraph needs to end with a clear thesis statement that indicates the purpose of your paper.
  • For assistance on writing Introductions & ConclusionsLinks to an external site. as well as Writing a Thesis StatementLinks to an external site., refer to the Writing Center resources.
• Must use at least three scholarly, peer-reviewed, and/or credible sources in addition to the course text.
  • The Scholarly, Peer-Reviewed, and Other Credible SourcesLinks to an external site. table offers additional guidance on appropriate source types. If you have questions about whether a specific source is appropriate for this assignment, please contact your instructor. Your instructor has the final say about the appropriateness of a specific source for a particular assignment.
  • To assist you in completing the research required for this assignment, view The University of Arizona Global Campus Library Quick ‘n’ DirtyLinks to an external site. tutorial, which introduces the University of Arizona Global Campus Library and the research process, and provides some library search tips.
• Must document any information used from sources in APA Style as outlined in the Writing Center’s APA: Citing Within Your PaperLinks to an external site. guide.
• Must include a separate references page that is formatted according to APA Style as outlined in the Writing Center. See the APA: Formatting Your References ListLinks to an external site. resource in the Writing Center for specifications.