Review Questions-firearms and tool marks PDF

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Summary

How to handle firearms at a crime scene and get them to a crim lab...

Description

Review Questions 1.

What is the NIBIN? a. Is a site that allows law enforcement to access photos and information about cases. It was created o of IBIS which is a database of images of bullets and casings to help others Identify their unknown bullets and casing.

2.

What is rifling? What two types of markings does this produce? a. Rifling is the groove pattern in a barrel of the gun which allows the bullet to spin its way out. This leads to grooves which are the low cut areas in the barrel and lands which are the raised areas between the grooves.

3.

What is a distance determination? How is this done? a. Distance determination is determining the distance between the target/victim and the gun. It is done by looking at the gunpowder residue left on the victim/target.

4. What is the Greiss Test? a. It is a chemical test that develops gunpowder residue patterns. 5. When a bullet is retrieved, how is it marked for identification purposes? What should be avoided? a. It is marked with the investigator’s initials. The initials are placed on the butt or tip of the bullet so they do not mess with the side because of the bullet markings.

Critical Thinking Questions 1.

If you found a firearm at a crime scene, what steps would you take in order to transport the weapon to the lab? a. I would first make sure that it is fully unloaded so it can not accidentally fire. I would then grab the firearm from the trigger guard place a tag with all the necessary identification, then I would place it in an evidence bag. I would be the one to deliver it because I found it and it is safer for the finder to transport it.

2.

Why do you think it might be useful to know the distance between a gun fired and its target? a. It would be useful in determining where the parties were lying or telling the truth.

3.

If you were in charge of retrieving bullets at a crime scene, what steps would you take to retrieve a bullet and take it to the crime lab? a. For retrieving bullets I would mark the tip with my initials and wrap the bullets in tissue then put them in a bag then mail them to the lab.

4. What are some of the challenges in analyzing tool marks? a. We do not know what angle or how much pressure was used to make marks to 100% prove the tool. There can multiple tools that make the same tool marks or a variety of the tool. That’s why the individual characteristics are more helpful to find. 5. Why is gunshot residue important for a forensic scientist? What are the potential complications with this type of evidence? a. It is important for forensic scientists because it can give information about the distance between the gun and a victim. If the gun is not found they are only able to estimate the distance and it is not as accurate. If they use a dierent gun or bullets they can get wrong test comparisons....