Reference no: EM133090975

Case Scenario

A young woman was found dead at her house. Two witnesses reported loud noises coming from the house. Upon arrival at the scene, the investigators found the window of the back door broken. Glass from the door was collected as the "known" glass sample and labeled as K1. Investigators identified a suspect that same day. A search warrant was issued, the suspect's clothing was also searched, and several glass fragments were recovered from the shirt and from the shoes and labeled as "questioned" samples, Q1 and Q2, respectively.

All samples were collected, labeled and submitted to the laboratory for comparison and analysis.

The suspect's alibi (proposition) is that he broke a decorative lamp at his home and got transferred glass on his clothing. He has never been in the proximity of the victim's house.

Methods of analysis:

The methods listed below were used for analysis. See the Appendix Glass information to access the results obtained at the laboratory.(The appendix glass is posted on the first page)
• Visual inspection (including microscope)
• Refractive Index (GRIM)
• Polarized Light Microscopy
• LA-ICP-MS

Question 1.
Part 1 - Glass Characterization
Item 1 (K1)
Physical Features:
Please list all the physical features observed for Item 1.
Indicate what type of glass is found based on physical characteristics flat, float glass, non-flat, tempered, non-tempered, container, decorative?
Explain your statement.
Tips: Use the appendix data to describe the results from the characterization of the glass received for analysis.

Question 2
Part 1 - Glass Characterization
Item 2 (Q1)
Physical Features:
Please list all the physical features observed for Item 2.
Indicate what type of glass is found based on physical characteristics flat, float glass, non-flat, tempered, non-tempered, container, decorative?
Explain your statement.

Question 3
Part 1 - Glass Characterization
Item 3 (Q2)
Physical Features:
Please list all the physical features observed for Item 3.
Indicate what type of glass is found based on physical characteristics flat, float glass, non-flat, tempered, non-tempered, container, decorative?
Explain your statement.

Question 4
Part 2 - Match criteria and summary of results for glass examinations
Provide a summary of the significant similarities or differences observed during the analysis.
Then, create a table similar to the one below to summarize the results. Use IN for indistinguishable (similar/match) or DS for distinguishable (exclusion/different).

Question 5
Part 3 - Evidence support
Based on the physical and chemical characteristics, does the evidence support the suspect's alibi?
Explain your answer.

Question 6
Part 4 - Analytical scheme used for analysis
For this particular case, why was elemental analysis useful to support the conclusions?
Explain your answer.

Question 7
Part 5 - Interpretation and significance of the findings
For the glass comparison of K1/Q1 and K1/Q2 comment separately and explain clearly how you arrivedto the conclusions. Include which factors increased or decreased the value of the glass evidence in this particular case.

Question 8
Part 6 - Reporting interpretation and conclusions of the findings
How would you state your findings in a report? (Use scientific wording as you would to submit a report to the lead investigator and/or court reporting results and conclusions). Support the results with the evidence (avoid subjective statements). Report the findings and conclusion.

Question 9
Part 6 - Reporting interpretation and conclusions of the findings
How would you describe the results and interpretation of these tests to a court? (Provide an explanation to a jury in simple yet accurate language, like explaining to a 5-year-old child)

Question 10
Part 1 - Paint Characterization
Item 1 (K1)
Physical Features:
List all the physical features observed for Item 1.
Chemical Characterization:
List the classification of each of the 2 top layers, start the description in order from top to bottom. *To achieve this, create a table identifying as many of the IR spectra peaks as possible.
*Tips: make sure you describe color, type of coat (clear coat, color coat, primer), whether or not is enamel or lacquer, polymer and any extender, pigment or decorative flake, for example a complete layer description example will be: Dark blue color coat acrylic melamine enamel with styrene modification, with titanium dioxide and metallic decorative flakes).

Question 11
Part 1 - Paint Characterization
Item 2 (Q1) paint from hydrant
Physical Features:
Please list all the physical features observed for Item 2.
Chemical Characterization:
List the classification of each of the layers, start the description in order from top to bottom. To achieve this, create a table identifying as many of the IR spectra peaks as possible.
Tips:make sure you describe color, type of coat (clear coat, color coat, primer), whether or not is enamel or lacquer, polymer and any extender, pigment or decorative flake, for example a complete layer description example will be: Dark blue color coat acrylic melamine enamel with styrene modification, with titanium dioxide and metallic decorative flakes).

Question 12
Part 2 - Interpretation and significance of findings
For the comparison of paint samples K1 and Q1, which factors increased or decreased the value of the paint evidence in this particular case?
Explain your answer.

Question 13
Part 3 - Reporting interpretation and conclusions of the findings
How would you state your findings in a report? (Use scientific wording as you would to submit a report to the lead investigator and/or court reporting results and conclusions). Support the results with the evidence (avoid subjective statements). Report the findings and conclusion.
Based on the overall findings, indicate if the paints are OEM or repainted.

Question 14
Part 4 - Evidence support
How does the paint evidence in this case supports the alibi of the suspect (defense proposition) or the prosecutor proposition (i.e., the suspect was involved in the criminal activity)?

Question 15
Part 5 - Interpretation
Given the analytical results reported in this case, would the PDQ database be useful to provide added significance/value to the evidence?
Explain your answer.

Attachment:- Exam case.rar