FORENSIC CHEMISTRY LABORATORY MANUAL

by R.Q. Thompson; Oberlin College

CASE OF THE

TRAMPLED TEEN

 

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Forward to the Case Report (Student Pages)

MAJOR EVIDENCE TECHNIQUES SET UP FOR A PARTICULAR CASE *

Blood Samples

  • from Rebecca Ferris
  • from Bradley Kimmer

 

Gas chromatography (ethanol)

Gas chromatography - mass spectrometry (drugs)

  • Ferris: ethanol (0 g/100 mL) ; cocaine (750 ng/mL)
  • Kimmer: ethanol (0.2 g/100 mL) ; cocaine (125 ng/mL)

Fabric Samples

  • from S. Argones' car
  • from Peter Bredon's car
  • from Brad Kimmer's car
  • from R. Ferris' shirt

Visible diffuse reflectance spec. (color)

FT-Raman spec. (composition)

  • Argones: 100% cotton
  • Bredon: 65/35 cotton/polyester
  • Kimmer: 50/50 cotton/polyester
  • Ferris: 50/50 cotton/polyester

Glass Samples

  • from S. Argones' car
  • from Peter Bredon's car
  • from Brad Kimmer's car
  • from crime scene

Microscopy, refractive index tests

Atomic absorption spectrophotometry (Mg)

  • Crime scene: several pieces of bottle glass, several pieces of headlamp glass from Kimmer's car, one piece of windshield glass of the type found in Bredon's car

Swab of Rebecca Ferris' shoes

Solid phase extraction & Liquid chromatography

(follow procedures described in explosives section)

  • Atrazine (a common herbicide) found on victim's shoes, indicating she had exited the corn field before entering the roadway.
White Powder from Peter Bredon Infrared spec. (bulk drug)
  • Mixture of starch and caffeine ("cocaine")

* ONE POSSIBLE SCENARIO: Rebecca Ferris, high on cocaine makes her way through a corn field before stepping onto a country road. Bradley Kimmer, intoxicated with alcohol and drugs and driving at high speed, collides with and kills Rebecca. He leaves her by the side of the road and drives on.