This paper discusses the significance of addressing operator use, field applications, and current and future needs, as part of the critical design process when developing tools for law enforcement use. As tools are developed for a specified law enforcement purpose, the officer using the device, the circumstances where it will be used, the intended results (lethal, non-lethal, less-than-lethal), risks, and environment need to be considered if the technology is truly going to meet officer needs. Through the use of human factors engineering and human performance optimization criteria as part of the design process, these issues can be evaluated at the time of conception, where needed changes may be made. These issues need to be addressed if technologies are to be developed or redesigned to meet the law enforcement use they are intended to address. If the technology does not meet its user's specific needs, capacity to use it, and ability to use it quickly if the application requires it, its use will be suspect, if it has applicability at all. Technologies for law enforcement, like other complex system settings, have to work as intended, under the conditions imposed, and work effectively if they will protect the user, others in the vicinity, and fit the application it is used in. These issues are not simple ones to answer, yet they are important in the early design phases as considerations to be evaluated before prototype development and full field application.