PART III.  INSTRUMENTS OF FORCE Since the adoption of the Basic Principles in 1990, there has been a significant evolution in the development of less-lethal weapons. Although some of these weapons are part of the more traditional instruments law enforcement officials are provided with, including the baton, there is a growing range of newly developed instruments, including chemical, blunt trauma, electric-shock, acoustic146 weapons and directed energy weapons,147 which should be issued only to small specialized units within the police. AN ADDITIONAL INSTRUMENT OF FORCE, RATHER THAN A SUBSTITUTE Issuance of less-lethal weapons may indeed lead to less reliance on using instruments that may cause death or serious injury (in this sense see principle 2 of the BPUFF), but this depends on the specific characteristics of the respective instrument, its effectiveness, the amount of pain it inflicts, and its place on the scale of force. Research has shown that in practice police use their less-lethal instruments of force not as a substitute for firearms, but in addition to the weapons arsenal they already have. As a result, less-lethal weapons do not lead to less use of firearms.a Also, less-lethal instruments are sometimes used as a punishment tool which may amount to ill-treatment and cannot be qualified as lawful use of force. a Other examples include millimetre-wave weapons that use focused beams of electro-magnetic radiation to heat the target; malodorants to affect a person or group of people; and optical weapons, such as lasers, disorienting LED or bright light, which use beams of light to affect the vision of the target; Dymond and Corney, “The use of ‘less-lethal’ weapons in law enforcement,” chapter 2, in Casey-Maslen (ed.), Weapons Under International Human Rights Law. Principle 3 of the BPUFF tasks States to “carefully evaluate” the development and deployment of less-lethal weapons and the use of such weapons should be “carefully controlled”. Often the scale of force is understood to go from non-lethal to less-lethal to lethal, but in practice the different instruments of force cannot be categorized so easily. Over the years, numerous studies have shown that some of the less-lethal instruments actually bear the risk of being lethal or causing serious injuries, depending on the type of instrument, but also on the context in which it is used and the characteristics as well as the health condition of the victim.148 It is important that there are clear and accessible national laws and internal law enforcement regulations that are in accordance with international human rights standards, stipulating for which types, how and when, different equipment or weapons can be used. States should also work together to implement international protocols for the training on and use of less-lethal weapons.149 Training should enable users to approach the use of these less-lethal instruments in a similar way to firearms, i.e. treating them as potentially lethal.150 146  Acoustic weapons, though they are neither lethal nor capable of inflicting visible injury, can cause significant pain and may even cause deafness. Moreover, they are unable to target a specific person and thus will invariably negatively impact on bystanders. 147  Other examples include millimetre-wave weapons that use focused beams of electro-magnetic radiation to heat the target; malodorants to affect a person or group of people; and optical weapons, such as lasers, disorienting LED or bright light, which use beams of light to affect the vision of the target; Dymond and Corney, “The use of ‘less-lethal’ weapons in law enforcement,” chapter 2, in Casey-Maslen (ed.), Weapons Under International Human Rights Law. op. cit. 148  See Report of the Special Rapporteur on extrajudicial, summary or arbitrary executions, 1 April 2014, paras. 101-107. 149  Joint report of the Special Rapporteur on the rights to freedom of peaceful assembly and or association and the Special Rapporteur on extrajudicial, summary or arbitrary executions on the proper management of assemblies, 2016, para. 55. 150  See Omega Research Foundation, Briefing for the Special Rapporteur on extrajudicial, summary or arbitrary executions, on the Use of Lethal Force during Arrest, 2011. 67