Firearm Analysis

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Firearm Analysis By: Kelsey Gardner, Mike Christiansen & Travis Becker.

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Firearm Analysis . By: Kelsey Gardner, Mike Christiansen & Travis Becker. Firearms. Firearm weapons are used for attack or defense. Firearms shoot a projectile by the force of the gases resulting from rapid combustion of an explosive mixture. Procedure. - PowerPoint PPT Presentation

Transcript of Firearm Analysis

Page 1: Firearm Analysis

Firearm Analysis By: Kelsey Gardner, Mike Christiansen &

Travis Becker.

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Firearms1. Firearm weapons are used for attack

or defense.2. Firearms shoot a projectile by the force

of the gases resulting from rapid combustion of an explosive mixture.

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ProcedureStep 1: The Comparison Process- test fire the firearm into a water tank in the lab.Step 2: Compare the test bullet to the recovered bullet from the crime scene or the victim using a comparison microscope.Step 3: look for an extractor mark, a breech face marking or a firing pin impression to see what was left on the cartridge casing, to link the suspect’s weapon to the crime.

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Cartridge Casings All cartridge casings have unique

marks on them. There are three different types of

firearm markings that examiners can use to determine casings fired from the same weapons.

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Firing Pin Impression The firing pin is forced into the primer cup

located at the rear center of the cartridge-this makes a firing pin impression.

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Breech Face Marking Once the cartridge powder is ignited by

the firing pin, the pressure exerts from the chamber, forcing the back of the cartridge case against the breech face of the weapon.

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Extractor Mark When a semi-automatic pistol is fired

the extractor pulls the cartridge from the chamber and ejects it from the pistol.

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Gun Shot Residue Many different elements can be studied

in the field of firearm analysis with gun shot residue (GSR) left on the clothes or skin of the person who fired the gun.

Washing of the body prior to examination can diminish or destroy gunshot residues.

Firearm Analysis Specialists can connect gun shot residue to a particular firearm, helping to solve a case.

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Sacco and Vanzetti This case was located in South Braintree,

Massachusetts on April 15th,1920. Nicola Sacco who was 29 and his companion

Bartolomeo Vanzetti, 32. They opened fired at helpless victims at the shoe

factory. The victims were heaving the payroll boxes into a waiting car. The killers escaped and they were seen as “Italian looking.”

They denied having guns but both were in possession of loaded hand guns that matched the murder weapon.

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Earliest Case This case was in 1835 and took place in London,

England. The servant of a homeowner was suspected to have

shot and killed him. Henry Goddard and a Police Officer found mold

marks on the fired projectile. They found a paper patch that had a torn newspaper

piece to seal the ball from the gunpowder. The newspaper was linked to the servant because

she had the newspaper in her room. Their careful observations and evidence brought the

suspect to be guilty.

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Biography Instructor Richard N. Ernest has over 30

years experience in this field and has won awards for being a forensic scientist.

Richard N. Ernest is a member of many scientific professional organizations and is a Distinguished Lifetime Member & Certified Firearms Examiner of the Association of Firearms & Tool Mark Examiners.

He went to the University of Georgia, where he received his Bachelor degree in Science.

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Works Cited http://dofs.gbi.georgia.gov/00/article/0,2086,75166109_75730713

_81669662,00.html http://fsi.research.wvu.edu/r/download/51102 http://firearmsid.com/A_historyoffirearmsID.htm http://library.med.utah.edu/WebPath/TUTORIAL/GUNS/

GUNGSR.htm