-34 CPT standards: The CPT has also set out specific standards on instruments of restraint in psychiatric establishments for adults.48 3.2.1.4. Conflict resolution, use of force and other means of coercion The use of force can be considered as a legitimate method for restoring security and order in prison, only if it is used as a last resort. In practice, this means that prison authorities must first and foremost aim to prevent and resolve conflicts49 before they escalate. To this extent, both the EPR and the Mandela Rules explicitly state that prison administrations are encouraged to use, to the extent possible, ‘conflict prevention, mediation or any other alternative dispute resolution mechanism to prevent disciplinary offences or to resolve conflicts’. Both instruments also refer to dynamic security, which is based on the idea that a good relationship between staff and prisoners can ensure that security threats are detected at an early stage and addressed through a process of dialogue and negotiation.50 Occasionally, situations may occur where staff are faced with incidents that require the use of force. Under international law, the use of force by law enforcement authorities is permitted only if in line with the four cumulative principles mentioned above: the principle of legality, the principle of necessity, the principle of proportionality and the principle of precaution. When it comes to the use of force, these principles are further spelled out by the UN Basic Principles on the Use of Force and Firearms, the Mandela Rules and the EPR.51 The ECtHR accepted that on occasion it may be necessary to use force in order to ensure prison security and to maintain order or prevent crime in detention facilities. However, it affirmed that violence can only be used if indispensable and in so far as it is not excessive. Hence, when a person 48. CPT, ‘Means of restraint in psychiatric establishments for adults’ CPT/Inf(2017)6 < https://rm.coe. int/16807001c3.> 49. Mandela Rules, Rules 38(1) and 76.1; EPR Rule 56.2, referring to the ‘use mechanisms of restoration and mediation to resolve disputes with and among prisoners’. 50. EPR Rules 64, 51.2; and Mandela Rules, Rule 76(c), where the concept of dynamic security is acknowledged under Art. 76(c) in relation to training for staff. 51. Mandela Rules, Rule 82; EPR 64-67; the UN Basic Principles on the Use of Force and Firearms by Law Enforcement Officials (1990) A/C0NF.144/28/Rev.l, Arts 15ff; UNGA, ‘Code of Conduct for Law Enforcement Officials’, Res 34/169 of 17 December 1979. For more details see SRT (Melzer) ‘ExtraCustodial Use of Force and the Prohibition of Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment’ (2017) A/72/178, §§ 5ff and 16.