Aaron Hernandez Trial Day 11 Part 1 (BPD Crime Lab - Amy Reynolds Testifies) | Summary and Q&A
TL;DR
Gunshot residue (GSR) testing is used to determine whether someone has come into contact with a fired weapon. The testing process involves collecting samples and analyzing them under a microscope. However, GSR testing cannot determine the source of the residue or provide conclusive evidence about a specific incident.
Key Insights
- 💁 Trace evidence, including gunshot residue, is important in criminal investigations as it can provide valuable information about the involvement of suspects and possible linkages to a crime scene.
- 🔬 Gunshot residue testing involves collecting samples from various surfaces and analyzing them under a microscope to identify the presence of GSR particles.
- 🌠 The presence of GSR particles does not provide conclusive evidence about the timing, circumstances, or source of a shooting incident.
Transcript
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Questions & Answers
Q: What is trace evidence, and why is it important in criminal investigations?
Trace evidence refers to small pieces of evidence that can be left at a crime scene and provide valuable information. It includes things like fibers, hair, glass, and gunshot residue. Trace evidence can help establish links between criminals and crime scenes.
Q: How is gunshot residue testing conducted, and what does it reveal?
Gunshot residue testing involves collecting samples using sticky stubs and analyzing them under a microscope. It reveals the presence of particles that are consistent with GSR, which is made up of lead, barium, and antimony. However, it cannot directly determine if someone has fired a gun or establish the timing or circumstances of a shooting.
Q: Can gunshot residue be easily removed or transferred?
Yes, gunshot residue particles are very small and can be easily removed or transferred. They can be wiped away or transferred from one surface to another through contact or environmental factors like wind or rain.
Q: Can gunshot residue testing provide conclusive evidence in a criminal case?
No, gunshot residue testing cannot provide conclusive evidence about a specific incident. The presence or absence of GSR particles does not prove or disprove someone's involvement in a shooting. It can only indicate contact with a recently fired weapon or objects with GSR particles.
Summary & Key Takeaways
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Trace evidence, including gunshot residue, is crucial in providing evidence in criminal cases.
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GSR particles are formed when a gun is fired, and they can be found on surfaces near the gun, such as hands, clothing, and objects.
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GSR testing involves collecting samples using sticky stubs and analyzing them under a scanning electron microscope to determine the presence of GSR particles.
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The presence or absence of GSR particles does not provide information about when or how a gun was fired, and factors such as cleaning or environmental conditions can affect the presence of GSR.