Introduction
While she was at work, someone busted Anya's car window and took her laptop, which was sitting in the front seat. Police watched the videos from the parking deck surveillance footage and identified three people who came and left the deck during the time the crime occurred. Police searched the homes of the three suspects and found a t-shirt with broken glass in one of the suspects homes. The suspect claimed the glass was from a bulb that broke while changing out light bulbs yesterday afternoon. How can investigators determine if this suspect's story is true?
In this section, you will learn various ways to analyze glass samples and the information that can be obtained from this common trace evidence.
Following successful completion of this lesson, students will be able to...
- Calculate the density of a sample of glass and use it to match a piece of glass to its source.
- Examine broken glass to determine the direction of the impact.
- Describe methods used to compare glass samples.
Essential Questions
- What is the difference between individual and class characteristics?
- How do you determine what evidence at a crime scene is valuable?
Enduring Understandings
- Forensic results are open to the interpretation and subject to the limitation of the pathologist's knowledge and methods.
- An exchange of material will occur whenever someone is at a crime scene (Locard's Exchange Principle). Materials left behind (or carried away) from the crime scene as well as markings and impressions from those items can be linked to an individual or item.
- The principles of scientific inquiry are required in all crime scene and forensic science analysis.
The above objectives correspond with the Alabama Course of Study: Forensic Science and Crime Scene Investigation standards: 25.