Are you having trouble viewing this email? View it online here: www.crime-scene-investigator.net/newsletter/0313.html
This message was not sent unsolicited. You signed up for this newsletter. If you wish to unsubscribe, please see the instructions at the bottom of this message.

Crime Scene Investigator Network

Crime Scene Investigator Network Newsletter

MARCH 2013
Welcome to the March 2013 Crime Scene Investigator Network Newsletter


Gun Shot Residue Testing
Is it Still a Viable Form of Physical Evidence?


Don Penven

Gun Shot Residue, or simply GSR, is a means of testing for the presence of certain materials on the hands and clothing of a subject in hopes of determining that this individual may have discharged a firearm. The concept is an old one and dates back many years. Advances in testing technology make this examination much more specific than it was some 30-40 years ago.

The Chemistry of Gunpowder
Most historians agree that the ancient Chinese discovered what we refer to as gunpowder. During the 9th century Taoist monks (alchemists) searching for an elixir of immortality accidentally stumbled upon the basic formula for black powder—a mixture of saltpeter (potassium nitrate), charcoal and sulfur. Later versions of gunpowder contain these same basic ingredients, but the overall chemistry evolved to include modifications that produced "smokeless gunpowder," Cordite, which eliminated the sulfur. Other advances added materials such as nitrocellulose (guncotton) and glycerol trinitrate (nitroglycerine).

Gunpowder—regardless of the formulation—has one specific purpose: the creation of oxides of carbon; in particular, carbon dioxide. The rapid creation of this gas is the propelling force that pushes a projectile (bullet) down through the barrel and on toward its intended target.

What is GSR?
Gunshot residue contains burned particles (potassium nitrite) and some unburned particles (potassium nitrate), and for decades criminal investigators collected these particles by applying melted paraffin wax to a subject's hands. Upon removal of the wax cast, a reagent containing diphenylamine and sulfuric acid was applied to the cast. The development of blue specks was indicative of the presence of nitrates.

But in the 1970s the courts took the position that the presence of nitrates in the environment was a common occurrence, and the dermal nitrate test was no longer a valid means to determine that the subject had fired a gun.

Primer Residue
When a gun is fired, the gunshot residue particles—small particles produced during the gunpowder explosions—are emitted from the back of the weapon and the muzzle. These particles fly onto the skin and clothing of the person

< read the complete article >

*Article submitted by the author

New CSI and Forensic Job Announcements

The most comprehensive listing of Crime Scene Investigation and Forensic
employment opportunities on the internet! We typically have over 100 current listings!

To be notified of job openings as they are posted, follow us on Twitter: <Receive Job Opening Alerts via Twitter>

Forensics Specialist II  |  Fremont (CA) Police Department
Final Filing Date: March 18, 2013
Salary: $65,816 - $80,000 per year depending on qualifications

The Forensics Specialist II is a journey level position that performs a variety of tasks in recognizing, processing, recovery, documentation and identification of physical evidence. Utilizing scientific methods in analysis, comparison and evaluation, the position conducts numerous laboratory tests, interprets results, prepares necessary notes, reports and exhibits, and testifies in court as an expert witness.

<View complete job listing>
Computer Forensic Examiner I  |  Towson, Maryland, Police Department
Final Filing Date: March 15, 2013
Salary: $45,630.00 - $56,836.00 Annually

Under general supervision, processes, examines and analyzes computer hardware, software, electronically stored data and other computer-related evidentiary materials pertaining to law enforcement investigations.
<View complete job listing>
Crime Laboratory Evidence Technician  |  Texas Department of Public Safety, Corpus Christi
Final Filing Date: March 7, 2013
Salary: $2,644.08 - $3,673.90 Monthly
Performs daily laboratory evidence technician duties to include receiving, storing, returning, and/or destroying crime evidence items according to court orders or to comply with applicable statutes and properly and accurately documenting transactions involving evidence receipt, disposition, inventory, and destruction. Assists laboratory personnel with inventory, disposition, and destruction of evidence stored in the laboratory vaults. Participates with laboratory personnel in preparing marijuana, pseudo drugs, and other controlled substances and training aids for Department canine operations. Transfers training aids to canine handlers and maintains records of all transactions. Assists chemists and other laboratory personnel with crime scene investigations when necessary. Performs general maintenance and trouble shooting activities within the Crime Laboratory Sections. Handles the majority of supply and chemical ordering and maintains supply order records.

<View complete job listing>


Property and Evidence Supervisor  |  State of Grand Prairie, Texas, Police Department
Final Filing Date: March 14, 2013
Salary: $42,426.00 - $67,883.00 Annually

The purpose of this position is to function as a working supervisor in the Police Property room. Position must organize the day to day operations of the property room as well as ensure the proper handling of evidence and property of the Police Department.

<View complete job listing>
Latent Print Examiner  |  Miami, Florida, Police Department
Final Filing Date: March 15, 2013
Salary: $57,005.31 - $76,558.35 Annually

This is specialized and technical work in latent fingerprint/palm print examination and identification within the Police Department. Work involves the examination, comparison, and identification of latent fingerprints/palm prints and other specialized methods utilizing chronology knowledge of latent print processing. Work includes the responsibility for the maintenance and identification of criminal evidential records and latent fingerprint/palm print evidence. Work is intellectual and varied in nature as opposed to routine mental, manual, mechanical, and physical work and involves the consistent exercise of judgment and discretion in its performance. Work may be performed on an assigned basis as part of an investigation/prosecution of criminal offenders. Direct supervision is received from the Senior Latent Print Examiner or designee who reviews work for completeness, technical quality, and adherence to departmental standards.

<View complete job listing>
Forensic Autopsy Technician  |  District Five Medical Examiner's Office (FL)
Final Filing Date: March 10, 2013
Salary: $28,000 or above, commensurate with the level of education and Forensic Autopsy experience.

The Forensic Autopsy Technicians working in this office are responsible for a wide variety of duties, including: assisting pathologists with autopsies and external examinations, preparing accurate records of processing, photographing bodies and evidence, maintaining morgue areas, supplies and equipment, overseeing the release of bodies to funeral homes, performing radiographs, assisting with the collection and labeling of evidentiary materials including toxicology and other laboratory samples.

<View complete job listing>
Search for more job listings in Crime Scene Investigations and Forensics
<Crime Scene Investigator Network Employment Listings>


To notified of job openings as they are posted, follow us on Twitter
<Receive Job Opening Alerts via Twitter>


CSI In The News

Oregon's DNA database makes its 5000th match
Oregon State Police hit a milestone when its forensic lab recently recorded its 5,000th match on DNA collected from crime scenes.
www.statesmanjournal.com - by Anna Staver - February 25, 2013

Justice proposes forensic science governing body
The Justice Department will create a committee to develop guidance and policy recommendations for forensic science and its use in court.
FierceGovernment - By Geoff Whiting - February 25, 2013

DNA privacy gets first Supreme Court test
The court's ruling, due by June, will be its first on the privacy of genetic information and will determine the fate of laws in at least 25 states that allow DNA collection at arrest.
Daily Herald - By Bloomberg News - February 23, 2013

Forensic makeover a top lab for all police
Airlocks and ''positive pressure'' will be used to prevent contamination of evidence in a new $105 million Australian Federal Police Forensic research complex.
Fairfax Media - by Peter Jean - February 23, 2013

Forensics Lab Goes Lean to Jump Start Productivity
Forensic biologists at the Monroe County Crime Laboratory in Rochester, N.Y., have increased the number of final reports they’ve issued by 200 percent, thanks in part to a lean management system.
Government Technology - By Brian Heaton - February 21, 2013

Louisiana moving ahead with expanded forensic science center in Shreveport
Louisiana gave the go-ahead Wednesday to seek bids to build a larger forensic science facility in Shreveport.
www.thetowntalk.com - - February 21, 2013

Forensic noise analysis helps to identify tampered photos
All digital cameras leave some trace of noise or imperfections on a photo when it is created. For most photographers, this noise is not a desirable feature. However, a new method of forensic analysis, developed by a team at the University of Albany, turns noise into something quite amazing.
CNET - By Lexy Savvides - February 21, 2013

Other Resources on the Crime Scene Investigator Network Website
Not Subscribed to this Newsletter?
If you are not subscribed to this newsletter, you may subscribe by clicking here: SUBSCRIBE

To Unsubscribe
To unsubscribe from future e-mail newsletters, please click here: UNSUBSCRIBE
or email newsletter@crime-scene-investigator.net with your request to unsubscribe.
Copyright ©2013 crime-scene-investigator.net

Crime Scene Investigator Network
PO Box 1043
Wildomar, CA 92595-1043

To ensure future delivery of Crime Scene Investigator Network newsletters to your inbox (not bulk or junk folders) please add our "from" address to your address book or e-mail whitelist.