Tag Archives: ballistics

Tracking Firearms in Toronto

Posted on by

CBC News report on firearm identification technology.

 

On May 13, CBC News posted an article entitled, “Bullets Decoded: Inside a Toronto Firearm Lab.” As detailed on the CBC News website, Toronto police use the Integrated Ballistics Identification System (IBIS) to analyze three-dimensional marks created on bullets and shell casings upon firing. The technology reveals links among crimes. In one case, for example, the same gun had been fired during two otherwise unrelated shootings and a bank robbery.

Developed by Montreal-based Forensic Technology, IBIS is used by Canadian and US police forces, as well as by other law enforcement agencies throughout the world. According to Robert Walsh, Forensic Technology’s CEO, IBIS has linked guns with more than 100,000 crimes in the United States alone.

IBIS’ success has not gone unnoticed by criminals. “I think the criminals have learned through the court system and word of mouth with each other that IBIS exists and it’s able to link up crimes to other crimes,” Toronto police detective Mike Grierson told CBC News. As a result, criminals sometimes “police their brass,” to avoid leaving evidence at a crime scene.

 

NIBIN

Posted on by
Case comparison

Photo shows two test-fired cartridge cases from the same firearm compared side-by-side with a comparison microscope. Source: Stephen G. Bunch et al., “Is a Match Really a Match? A Primer on the Procedures and Validity of Firearm and Toolmark Identification,” Forensic Science Communications 11(3) (July 2009).

 

Fourteen years ago the ATF (today, called the Bureau of Alcohol, Tobacco, Firearms and Explosives) set up the National Integrated Ballistic Information Network (NIBIN). US partners of this network use Integrated Ballistic Identification Systems (IBIS) to obtain digital images of marks on fired cartridge cases and bullets. These cases and bullets are either recovered from a crime scene or from a test firing of a suspect weapon. The images are electronically compared with stored NIBIN entries. On TV shows, an electronic match – a hit – often ends the investigation. In real life, a high-confidence electronic match means that a firearms examiner compares original evidence with a microscope to confirm the match. So far, NIBIN partners have confirmed more than 50,000 NIBIN hits.

Last month, KVOA’s Lupita Murillo in Tucson reported a practical problem with NIBIN analysis. Although an electronic comparison may only require hours, somebody has to acquire and upload digital images into the network. The Tucson Police Crime Lab had 1,200 backlogged cases that needed to be entered into the system.

 

Forensic Firearms Identification

Posted on by
Silver to bullets

Poster printed by Sir Joseph Causton & Sons, Ltd, London, 1915. Source: Library of Congress.

Forensic firearm examiners determine whether a certain weapon fired a bullet or cartridge found at a crime scene. Early efforts linked spent ammunition with a class of weapon. Following the 1862 shooting of Confederate General Stonewall Jackson, for example, investigators concluded that the General had been accidentally shot by his own side. The spherical projectile removed from the General had been fired from a smooth-bore musket, a type of weapon that the Union Army no longer used.

In 1912, Professor Victor Balthazard at the University of Paris formulated the basic principles of firearms examination. Using enlarged photographs, he compared marks created by a firearm on the surface of bullets and cartridge cases found at a crime scene with marks on ammunition that he had fired from a suspect weapon. In this way, he could connect crime scene ammunition to a particular firearm.

During the 1920s in New York, four men rediscovered Balthazard’s principles and initiated modern firearms identification: Charles E. Waite, Calvin Goddard, Philip O. Gravelle, and John E. Fisher. Gravelle had extensive experience with a comparison microscope to study fine details in cloth patterns. He suggested that they might be able to use the instrument to compare fired bullets and cases.

In a signal event of firearms identification, the group bought two comparison microscopes and modified them. They added a comparison bridge, and rotatable mounts for bullets and cartridge cases. Through the eyepiece of the bridge, two pieces of spent ammunition could be examined, one on each stage of the two microscopes.

Police departments and the courts became aware of the value of “fingerprinting” bullets, especially after Goddard testified about his findings in the 1929 St. Valentine’s Day Massacre. Within a decade, firearms identification became an established technique of criminal investigation.

Microstamping Could Yield Macro Benefits

Posted on by

Example of microstamp placement

 

Traditional firearm identification is based upon the fact that every weapon has unique features introduced during manufacture and later caused by wear. These characteristics of a firearm create striated and impressed marks on fired ammunition that enable an examiner to identify a round of fired ammunition as coming from a particular gun. This analysis requires an examiner to have access to a suspect firearm that can be test fired to produce a bullet and cartridge case.

A method called microstamping could radically change firearm identification practice. Using lasers, unique alpha-numeric codes are added to certain parts of a firearm, such as the firing pin and breech face, and these identifiers are stamped onto a cartridge when fired. A code could reveal a firearm’s manufacturer, model, and serial number. The serial number alone would lead investigators to the identity of the person who first purchased the firearm.

Proponents of microstamping claim that the technique would not only aid a criminal investigation, but also would reduce the supply of illegal firearms. Microstamping, the argument goes, would deter people with clean records (straw buyers) from purchasing guns for criminals.

Since the technique was proposed, microstamping has generated controversy about the method’s reliability. A study posted on the New Yorkers Against Gun Violence website indicates that microstamping works.