Page 10 - Jagged Edge Glass Fragment
P. 10
POST-Lab
Solutions
1. Based upon your experimentally determined from the abandoned truck, as the glass from
refractive indices of both the bottle glass and any vehicle with the same headlight as the
headlight glass, which medium would change abandoned truck cannot be excluded as the
the path of light traveling through it the source of the glass found at the crime scene.
most?
Bottle Glass
4. Based upon your knowledge of the crime(s)
and your examination of the evidence
2. Did you determine the glass collected presented, what is your hypothesis about
from the site near the vehicle crash to be the events surrounding the deposition of the
consistent with the glass collected from broken glass?
the truck’s broken headlight? Explain your Answers will vary. As examination of the glass
reasoning. fragments should conclude that the broken
Yes, reasoning will vary, but both samples headlight from the truck cannot be excluded
should have a similar refractive index. as the source of the glass on the roadway near
the vehicle crash, students should suspect the
truck’s involvement in the crash.
3. Based upon your examination of the evidence
presented, can it be concluded that the
abandoned truck’s broken headlight produced 5. If further comparison of the glasses was
the broken glass on the road near the desired, what techniques could be utilized?
Backbone Mountain crash site? X-ray Diffraction (XRD) or Laser Ablation-
No, the evidence presented cannot prove Inductively Coupled Plasma-Mass
decisively that glass fragments collected from Spectrometry (LA-ICP-MS)
the crime scene match the headlight lens
10 THE MYSTERY OF LYLE AND LOUISE
