Misuse of handguns is a significant factor in deaths, morbidity, and crime in the United States. One approach to reducing certain types of handgun misuse is to create a user-authorized handgun (UAHG), a firearm that can be operated only by an authorized user(s). For the past decade, a handful of gun manufacturers, several university research groups, and a number of private research and development (R&D) groups have been exploring potential technologies for such a weapon.
The majority of this research, funded by the federal government through the National Institute of Justice (NIJ), part of the U.S. Department of Justice (DOJ), has been focused on the needs of the law-enforcement community. The level of investment has been modest, however, given the engineering challenges associated with developing a reliable UAHG. The total, including federal and state support, has been less than $12 million,1 much of it for very preliminary proof-of-concept research. Gun manufacturers have spent very little of their own money on this research, and, at this time, NIJ has no plans to support additional research.
In 2002, the National Academy of Engineering (NAE) sponsored a one-day workshop that touched on three topics: the status and potential of
technologies for UAHGs; the impact of UAHGs on public health and crime; and liability issues (NAE, 2003). In spring 2004, NAE formed the Committee on User-Authorized Handguns, whose members include research engineers, experts in manufacturing, and individuals experienced in handgun design and testing, to conduct the current study, which is focused exclusively on the technical aspects of developing a UAHG. This study is funded in part by a grant from The David and Lucile Packard Foundation.
GOAL AND OBJECTIVES
The goal of this project is to clarify the technical challenges of developing a reliable UAHG. The goal has four specific objectives:
Objective 1. Determine the requirements (e.g., reliability, environmental constraints, multiple-user capability) of UAHGs for two classes of owner: (1) people responsible for public safety (i.e., law-enforcement personnel); and (2) people concerned with personal safety and handgun misuse, particularly by children, in the home (i.e., homeowners).2
Objective 2. Based on these requirements, determine the specifications for UAHGs (e.g., time and ease of arming, time and ease of defeating the mechanism, definition of the fail-safe mode, size, weight).
Objective 3. Determine which technologies can satisfy the requirements and specifications among existing technologies, extensions of existing technologies, and new technologies that could be available in a reasonable time frame.
Objective 4. Assess the manufacturability and costs of the most promising technologies and estimate when they might become available commercially (“technology-readiness assessment”).
REQUIREMENTS AND SPECIFICATIONS
In addressing the first two objectives, the committee relied heavily on work conducted by Sandia National Laboratories (SNL, 1996, 2001). The Sandia studies addressed only the needs of those concerned with public safety (i.e., law enforcement). The researchers surveyed the law-enforcement community to ascertain their requirements for a UAHG and translated a number of these general requirements into detailed “specifications.” Although all of the requirements and specifications are important, the committee placed the highest priority on three vital categories—reliability, failure mode, and authentication.
In addition to the basic structure of the gun body, two critical kinds of technology must be part of any UAHG: (1) the authentication system and (2) the technology that permits or prevents firing of the weapon. For authentication to work, the gun user must have a unique identifier recognized by the handgun. The committee considered two classes of authentication technology—biometrics and token-based systems. Although at least a dozen biometric-based recognition technologies are being investigated for all kinds of systems, at this time only five (fingerprint, voice recognition, skin texture, skin spectroscopy, and handgrip pressure) are potentially appropriate for UAHGs. Of these, only two are being adapted for handguns: skin spectroscopy (by Smith & Wesson [S&W]) and handgrip pressure (by the New Jersey Institute of Technology [NJIT]).
Only one token-based technology (based on radio-frequency identification [RFID]) is in development for a UAHG at the present time. RFID systems generally consist of readers and transponders; each transponder (called an RFID tag) is associated with an entity to be identified. Transponders may be attached to, embedded in, or in proximity to the entity to be identified. If embedded, the tag becomes a “virtual biometric” that is permanently or semi-permanently associated with an individual. FN Manufacturing is working on a system with the Verichip (which has been approved by the Food and Drug Administration), an RFID tag that can be embedded under the skin (Applied Digital Solutions, 2004). The committee concluded that only embedded tags are appropriate for UAHGs.
Whichever authentication mechanism is used, it must interface with a latching mechanism on board the gun. Presently, handguns have
mechanical latching mechanisms that cock and release the hammer, which drives the firing pin into the primer. Gun companies have considerable competence and experience in designing latching systems. This does not mean, however, that engineering and production of the latching mechanism is simple. First, handguns require precision manufacturing to be reliable. Second, they are very compact, which means they have limited clearances for the addition of new electromechanical mechanisms to drive the latch. An alternative to an electromechanical latching mechanism is an all-electronic firing mechanism, which requires a special primer. This technology exists and has been used both commercially (in a rifle) and experimentally (in a prototype handgun by S&W). The choice of authentication technology will affect the failure mode of the firearm independent of latching/firing technology. An all-electronic handgun that loses electrical power to its authentication scheme can fail in the disarmed or armed mode, because power can still be available for firing.
Neither the S&W skin-spectroscopy nor the NJIT handgrip-pressure authorization technology has reached the level of discrimination required either for the law enforcement community or homeowners. Both technologies are at a breadboard stage;3 although the sensor is in a realistic configuration in the gun, the electronics for the reader are still external to the gun.
In judging the maturity of the technological components of a UAHG, the committee relied on a scale of technology-readiness levels (TRLs)4 used by the National Aeronautics and Space Administration and the U.S. Department of Defense to gauge the maturity of technologies in development (GAO, 1999). Based on this rating system, the committee believes both the skin-spectroscopy and handgrip-pressure technologies are at TRL 4.5
Because RFID systems are being developed for other applications, such as access control, they have reached a considerable level of maturity. Tag technology is highly developed, and even the embedded RFID sensor, which involves more complexity, has reached TRL 76 or TRL 8.7 However, most current applications of RFID systems do not require miniaturization of the reader. Because considerable technology development will still be necessary to fit the reader electronics into the gun, the commmittee believes the integrated RFID reader for a UAHG is currently at TRL 58 or lower.
Some people in the gun industry believe that modifying the mechanical latching system by introducing an electronic interface may compromise the weapon’s reliability. Nonetheless, FN Manufacturing has chosen to take the mechanical latch approach. Although an electromechnical latch may not be the most elegant solution, at this point in time, the committee believes such a latching scheme could be brought to TRL 69 in relatively short order, if FN has not done so already.
With respect to electronic firing, S&W has reported firing 60,000 rounds of electronically activated ammunition with prototype weapons with no reliability or power-source limitations (Kevin Foley, S&W, personal communication, 4/20/05). The firing electronics were fully integrated into the gun, and based on S&W’s reported testing, the committee judges that this implementation of an electronic firing mechanism is at least at TRL 6, and possibly TRL 7.
Metal Storm, an Australian defense research company, has explored a radically different design for an electronically fired handgun in which the projectiles are stacked in the barrel and fired in sequence. NJIT has entered a partnership with Metal Storm with the hope of integrating its grip-pressure recognition technology into the new handgun design (NJIT, 2003). However, because this is a rather new concept and even the ammunition will require a development project, the committee judges that this technology could be anywhere from TRL 310 to TRL 5.
Developing a UAHG for law enforcement poses serious engineering challenges: the need for a very low false-rejection rate and the need for the firearm to function in inclement environmental conditions, high-stress situations, in the presence of dirt, and with users who might wear gloves. In terms of the likelihood of successful development, both the skin-spectroscopy and handgrip-pressure technologies under development are unproven, high-risk technologies. RFID sensing appears to be a relatively low-risk technology, in the sense that it has an extensive and well documented track record in other applications. But, like biometric sensors, it would require miniaturized components in the gun, which is not a trivial undertaking.
Even a UAHG for homeowners, who may have less daunting authentication requirements, poses significant technical challenges. Inclement weather, dirt, and gloves would not be significant factors, but the need for recognition of an authorized user in a stressful situation would be just as demanding for the authentication sensor, and the gun should share the requirement of a law enforcement gun of being extremely difficult for an unauthorized person intentionally to bypass the security system by what-ever means possible. However, if the emphasis is placed on the rejection of an unauthorized user, especially a child, the demands on the sensor are likely to be somewhat less stringent than for law enforcement. In this case, the product designer must chose between the “perfect” solution and the “good” solution.
Developing a reliable UAHG will require technologies that are beyond the experience base of gun companies. And, that experience base has kept the development costs of conventional guns fairly low. Through the NIJ program, S&W, FN Manufacturing, and NJIT have each already spent, or will soon have spent, amounts approaching the development cost of a conventional gun (on the order of $3 million to $4 million; see Appendix D) and, in the committee’s judgment, all of them are still a long way from having developed integrated brass-board test articles11 (i.e., TRL 5 devices), even though individual component technologies may be more mature. In addition, the monies spent to this point are early-stage costs; typically, absent an experience base, development costs escalate rapidly at this point. The committee estimates that total costs to bring a single implementation of a UAHG to market could easily reach several times to as much as 10 times what each developer has spent to date, or on the order of $30 million, particularly for a version that uses true biometric authentication and could take 5 to 10 years to complete. If one were to start anew, with present developments as the baseline, the committee suggests that the shortest path to success, with cost and time at the lower ends of these ranges, would involve a mechanical or electronic gun interfaced with an RFID tag inserted under the skin. Recent progress in the development of a UAHG has been almost solely the result of research funded by NIJ. However, there is no follow-on funding in the 2005 fiscal year federal budget for this program (Christopher Miles, NIJ, personal communication, 9/13/04). The committee is not aware of any substantive developments outside the NIJ program and expects the present development efforts to come to an end if and when NIJ funding is exhausted.
Applied Digital Solutions. 2004. Verichip Corporation enters into a memorandum of understanding for the development of a firearm’s user authorization system—“Smart Gun”—using Verichip RFID technology. Press release. Available online at: http://www.adsx.com/news/2004/041304.html (February 13, 2005).
GAO (General Accounting Office). 1999. Best Practices: Better Management of Technology Development Can Improve Weapon System Outcomes, edited by L. Rodrigues and P. Francis. GAO/NSIAD-99-162, July, 1999. Washington, D.C.: General Accounting Office. Available online at: http:/www.gao.gov/archive/1999/ns991620.pdf.
NAE (National Academy of Engineering). 2003. Owner-Authorized Handguns: A Workshop Summary, edited by L.A. Davis and G. Pearson. Washington, D.C.: National Academies Press.
NJIT (New Jersey Institute of Technology). 2003. New Jersey Institute of Technology moves ahead to get smart gun on market. Press release, September 5, 2003. Available online at http://www.njit.edu/v2/News/Releases/395.html. (April 20, 2005)
SNL (Sandia National Laboratories). 1996. Smart Gun Technology Project Final Report, edited by D.R. Weiss. SAND-96-1131. Available from National Technical Information Service, Springfield, Va. NTIS Order Number: DE96013854.
SNL. 2001. Smart Gun Technology Update, edited by J.W. Wirsbinski. SAND-2001-3499. Available from National Technical Information Service, Springfield, Va. NTIS Order Number: DE2001-789587.