Modern technology for stria comparison

In 1989, the drug-related crime in Washington DC, USA, reached a stage where the law enforcement agencies were forced to implement a 'war on drugs' campaign. As a result, the forensic laboratories became overwhelmed with the quantity of fired ammunition submitted. In an attempt to assist the forensic laboratories as much as possible, 'target' cases were selected by the Federal Bureau of Investigation (FBI) for special attention.

Comparing each bullet and cartridge case in this list with those from a submitted case was, however, still, very manpower intensive. To simplify matters, large photographs of the bullets and cartridge cases from the targeted cases were pinned onto the wall behind the comparison microscopes. The examiner could use these photographs as a rough screen to determine whether there were any similarities between the exhibits on the comparison microscope and those on the wall. If there were, then the relevant exhibit would be taken from the Outstanding Crime Index (OCI) and compared directly on the microscope.

Realizing that this could be carried out more effectively with the use of modern technology, the FBI sponsored research into digitalizing the photographs. These were displayed on a high- resolution computer screen in a tiled pattern surrounding the exhibit under examination. The system was called 'Drugfire'.

Drugfire went through a series of developments until eventually, it utilized computer-based comparison algorithms for the matching of stria on digitized images of the fired cartridge cases and bullets. In its eventual form, it was a highly effective system.

Around the same time as the FBI contract was issued, the Bureau of Alcohol, Tobacco and Firearms (ATF) established its own automated ballistics identification system. However, instead of developing a custom-made system like the FBI, the ATF opted to build its network on an existing platform which had already been developed by Forensic Technology Inc. (FTI) for general industrial comparison purposes.

From the very start, the FTI system utilized computer-based comparison algorithms and did not have to go through the same developmental process as Drugfire.

Initially, the system was only capable of comparing bullets and was called Bulletproof. Later, it was upgraded to handle cartridge cases and was then renamed the Integrated Ballistic Identification System (IBIS).

As a result, from 1993 to 1998, the United States had two, non-capable, automated ballistics identification systems in place: Drugfire, which was under the FBI, and IBIS, under the ATF. Although there were attempts to interconnect the two systems under the National Integrated Ballistic Identification Network (NIBIN), it was not successful.

In 1999, the FBI and ATF finally decided to phase out Drugfire and to standardize NIBIN on the IBIS platform. This decision was arrived at after a thorough joint FBI-ATF evaluation revealed the superiority of IBIS over the other system.

The adoption of IBIS as the NIBIN standard made FTI the world 's biggest manufacturer of automated ballistic identification systems.

In 2005, FTI released its 'Bullet TRAX' and in 2006, the 'Brass TRAX' systems which enabled both 2D and 3D imaging of bullet and cartridge case stria. This not only enabled users to take qualitative measurements of the surface topography of a bullet and cartridge case, but also considerably enhanced the capability of the IBIS system.

Examples of 3D imaging follow (Figures 4.1 and 4.2).

A number of other ballistic identification systems are also in the market, including:

• ARSENAL by Papillon Systems of Russia;

• EVOFINDER by SCANBII Technology;

• TAIS, another Russian system;

Tais Another Russian System
Figure 4.1 Three-dimensional imaging of rifling stria. Image reproduced by permission of Forensic Technology Inc.
Forensic Technology
Figure 4.2 Three-dimensional imaging of firing pin indentation on a primer. Image reproduced by permission of Forensic Technology Inc.

• BALISTIKA from Turkey;

• FIREBALL from Australia.

There are also a large number of issued patents covering this technology, so more systems can be expected in the future.

It should be strongly emphasized that these systems cannot, at present, replace the comparison microscopist. All they do is generate a list of 10 or 20 top candidates as possible matches. The firearms examiner uses this list to select the actual bullets/cartridge cases from the OCI for visual examination on a comparison microscope.

It is the examiner who makes the final decision as to whether there is a match, and it is he or she who testifies to this in court.

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  • medhanit
    What are stria How are they used in forensic firearms examination?
    5 years ago
  • ursula
    What are stria in the forensic world?
    4 years ago
  • Lotta
    What is stria in gi tract?
    9 months ago
  • ambrosia
    What are stria and how do they occur forensics?
    6 months ago
  • JUANITA
    What are stria and how do they occur in ballistics?
    3 days ago

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