72 Resource book on the use of force and firearms in law enforcement SCALING UP, SCALING DOWN Law enforcement officials should bear in mind that situations change, and the use of force may be justified at a certain point, but this may change while the incident is happening. As one police chief mentioned during a conference organized by the Police Executive Research Forum (PERF) on this issue: “One of the things that I’ve discovered during my time as a police officer is that it’s easy for us to go up the use-of-force continuum, but the hard part is bringing it back down, and de-escalating situations effectively. These are dynamic events that are taking place. An officer may be justified in using a certain level of force at one moment in time, but that doesn’t necessarily mean that the same window is open three, four, five seconds later in an unfolding event”.a a See Police Executive Research Forum (PERF),2012, p. 1; Terrill, W. E. A. Paoline III and J. Ingram, Final Technical Report Draft: Assessing Police Use of Force Policy and Outcomes. NCJRS, Feb. 2012: https://www.ncjrs.gov/pdffiles1/nij/grants/237794.pdf Although models like these can be useful, they are also criticized for a number of reasons. They are said to hamper decision-making, raising fear of liability issues, and may fail to take into account the particular qualities and skills that individuals or groups of police personnel may bring to the situation. A problem with many use-of-force models is that they are based on a principle of “use of violence encountered + 1”, which entails that the law enforcement official should always be one step ahead of the violence encountered. Consequently, their use may actually lead to an escalation of violence, rather than allow for the opportunity to de-escalate, possibly leading to use of force that fails to meet the requirements of necessity and proportionality. THE NATIONAL DECISION MODEL, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND a The United Kingdom has moved away from use-of-force models that follow a scale of force, but instead adopted the National Decision Model. The model is generic and can be applied both to spontaneous incidents and planned operations; whether carried out by an individual or team of people; and to both operational and non-operational situations. It has six key elements. At the heart is the code of ethics, containing the principles and standards of professional behaviour that should guide all police action and decisions. The model starts with gathering information and intelligence; assessing threats and risks and developing a working strategy; considering powers and policy; identifying options and contingencies; then taking action; and reviewing what happened. The model is cyclic, in that this action then provides new information, which in turn needs to be assessed. Decisions taken need to be recorded and be subject to review. a See College of Policing, National Decision Model, 2014. The type of policy that is most suitable for a particular context should be contingent on the context in which it will be used: in countries where discretion is seen to lead to many incidents of abuse of force, a policy may help to bring that down. However, adopting a policy will not