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Ballistic Imaging (2008) / Chapter Skim
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PART IV: Future Directions, 10 Microstamping: Alternative Technology for Tracing to Point of Sale
Pages 253-271

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From page 253...
... PART IV Future Directions
From page 255...
... If such known markings -- for instance, a gun-specific alphanumeric code -- are logged at the point of sale, the same goal as a national image database would be achieved: a spent casing recovered at a later crime scene could be rapidly traced back to the point of sale by reading the etched marking. Likewise, known and individual markers could be placed directly on individual pieces of ammunition; again, if the component codes in a box of ammunition are logged at the point of sale, investigative leads could result later in time when pieces of stamped ammunition are found at crime scenes.
From page 256...
... Because serial numbers can link manufactured objects to their owners, they provide a valuable tool to law enforcement in developing leads in criminal cases. Two well-known illustrations of the utility of serial numbers in investigating criminal cases -- the bombings of the World Trade Center in New York in 1993 and of the Alfred P
From page 257...
... Investigators sifting through the rubble in the parking garage under the World Trade Center following the 1993 bomb explosion found fragments bearing a VIN corresponding to the number of a missing van. Tracing the van to a Ryder truck rental agency led to the arrest of a suspect in the bombing; leading in turn to the capture of additional suspects (Parachini, 2000)
From page 258...
... However, the Assembly and Senate could not agree on a conference version of the bill before the end of the 2006 legislative session. The second bill, Senate Bill 357, would have required all handgun ammunition manufactured or imported into California for sale or personal The roll call on the vote was 20–19 in favor, but 21 votes are needed for passage in the 40-member Senate.
From page 259...
... on interest expressed by New Jersey law enforcement officials in microstamping of firing pins. Though the microstamping proposal was not enacted, Senate Bill 357 was in fact passed into law; in August 2006, the bill was amended to strike the entire text relating to microstamped ammunition and was replaced with language on collective bargaining with state employees.
From page 260...
... The study concluded that the principal markings on the stamped firing pins remained legible on repeated firings but that finer markings (e.g., striations left by a barcode etched on the side of the firing pin) were subject to wear; microstamping was said to hold promise but required further research.
From page 261...
... Specifically, the proposed legislation would forbid the manufacture or import of any "firearm that is not microstamped or a microstamped firearm that does not transfer the array of characters constituting the microstamp onto the cartridge case of any ammunition fired from the firearm." The bill, H.R. 5073, specifically defines a microstamp as "an array of characters which identify the make, model, and serial number of the firearm" that is "etched into the interior surface or internal working parts of the firearm." Although it no longer called for creation of an image database, the new legislative text retained language from previous versions that requires "ballistics testing of any firearm in the custody of the Federal Government" and establishment of "an electronic database containing records of the results of the testing" that can be accessed by state and local law enforcement agencies.
From page 262...
... The identifying mark is created when the pin hits the primer surface of the cartridge, and the "image" of the microstamp marking can be read in the base of the firing pin impression on the recovered casing. The microstamped markings are created by ultraviolet (UV)
From page 263...
... concluded that the firing pin scrape in the Glock did not degrade the microstamped identifier and that neither lacquered primers nor variation in primer finish and hardness affected the microstamp's ability to impart a fixed marking.
From page 264...
... . and the weapon would have still functioned." Although much of the initial work done to date has focused on placing microstamped identifiers on firing pins (thus marking cartridge casings)
From page 265...
... Conceivably, some identifiers could even be read at crime scenes using a hand magnifying lens, saving considerable time. Again assuming a clear impression, identification based on a microstamped marker is also easier to explain and interpret, as it does not require the subjective judgment that is now central to the interpretation of toolmarks left on a spent cartridge case.
From page 266...
... Similarly, such strategies would also be hindered in instances in which suspects remove spent casings from crime scenes. • Firing pins can be replaced with relative ease, so a single microstamped identifier could be defeated by swapping in a new pin.
From page 267...
... 10–D  Microstamping of Ammunition As described above, the microstamping of firearms -- as currently conceived -- is principally about imposing marks on expended cartridge casings. Hence, as would be true in a cartridge case-only national RBID, it would not work in settings in which casings are not expelled at crime scenes (e.g., revolvers are used)
From page 268...
... Later, when a microstamped bullet is recovered at a crime scene, the individual bullet code would be read and matched to an exterior box code; that box code would in turn provide the lead to the point of sale. ACS-marked ammunition was subjected to two tests by California law enforcement personnel.
From page 269...
... • The base of a bullet -- the proposed area for the microstamped identifiers to be located -- is more likely to avoid warping or deformation when the bullet hits a target, relative to the striation marks on the side of the bullet. • The process of reading a code on a recovered bullet is a relatively quick one, and in some cases may be possible at the crime scene itself.
From page 270...
... Moreover, in complex crime scenes where multiple firearms are discharged, microstamped bullet markings could not directly lead to connections between specific bullets and the guns that fired them. • Though individual records would be much simpler than in an image database, ammunition microstamping would require a new database of massive scope, providing the mapping from codes on individual rounds of ammunition to the code on the box of ammunition that contained them.
From page 271...
... However, we do conclude that state and federal law enforcement would be better served by new technologies and systems developed through richer and more open competitions, by multiple vendors and research teams and with fuller appreciation for the integration of new systems with existing manufacturing practices.


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