Your editorial "Getting down to brass tags" (June 14) left out a few facts that might give your readers a clearer view of the value of adding microstamping technology to pistols as a way of tracing spent shell casings found at crime scenes to a particular handgun. Independent studies by the National Academy of Science, by the University of California at Davis, and by George Krivosta of the American Society of Firearm and Toolmark Examiners concluded the technology is underdeveloped, producing inaccurate results that are easily circumvented, either on purpose or by simple use of the firearm within a few number of rounds fired. Mandates to use this technology come from its sole source inventor who stands to benefit substantially when firearm manufacturers must come to him to learn how to apply microstamping to their products. The cost of $12 per gun comes from advocates of the technology. Firearm manufacturers estimate the cost at around $200 per gun.