Skip to Content

Disaster at the Daisys’

The Analysis of Forensic Evidence


Author(s)

Kimberly S. Farah
Applied Forensic Science
Lasell College
kfarah@lasell.edu

Abstract

This directed case study was written to help students understand both organic and inorganic analysis of forensic evidence. It tells the story of a fire at the home of Mr. and Mrs. Daisy who are found deceased on the property, both with gunshot wounds. Students assume the role of forensic investigators as they attempt to determine whether the gunpowder pattern evidence points to homicide or suicide. A series of questions guides students through an investigation of pattern evidence and accelerants so that they can develop a hypothesis about the crime. Students must also determine the instrumental methods of analysis needed for the analysis of evidence. This case study was designed for a forensic science course for non-science majors, but could also be used at the high school level or adapted for an instrumental methods course or an organic chemistry course.


Objectives

  • Use gunpowder residue evidence as a basis for determining the approximate distance from which a shot was fired.
  • Identify the types of elements that are typically found in gunshot residue.
  • Differentiate between destructive and non-destructive analytical methods.
  • Understand the significance of pattern evidence in arson investigations.
  • Differentiate between types of accelerants.
  • Understand how flammable residue is analyzed.

Keywords

Instrumental analysis; gas chromatography; headspace analysis; solid phase extraction; gunpowder residue; criminal investigation; forensic investigation; forensic analysis; arson

Topical Areas

N/A

Educational Level

High school, Undergraduate lower division, Undergraduate upper division

Format

PDF

Type / Methods

Directed

Language

English

Subject Headings

Forensic Science  |   Chemistry (General)  |   Analytical Chemistry  |   Organic Chemistry  |  


Date Posted

1/23/2019

Teaching Notes

Case teaching notes are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.

Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Answer Key

Answer keys for the cases in our collection are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.

Videos

The following video(s) are recommended for use in association with this case study.

  • Gas Chromatography GC
    Demonstration of gas chromatography using a flame ionisation detector (FID) with a brief mention of gas chromatography mass spectrometry (GCMS). Running time: 5:16 min. Produced by Royal Society of Chemistry, 2008.
  • Atomic Absorption Spectrometer
    Demonstration of the standard operating procedure for the Varian Spectra Atomic Absorption Spectrometer. Running time: 10:28 min. Produced Gary Mabbott, 2016.
  • Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES)
    Demonstration of ICP-OES. Running time: 4:03 min. Produced by Virtual Soil Science Learning Resources, 2014.

Comments