62 Human Rights in Counter-Terrorism Investigations Crime scenes can be dangerous. Bomb explosions almost always leave buildings in an unsafe condition, posing grave danger for members of the emergency and security services, and for people who may be in the vicinity. Where the explosion has been caused by a large device, such as a car bomb, the damage and instability may extend over a large area of a city. Debris from the explosion is likely to be scattered. Unexploded devices pose similar dangers. The job of the police in these circumstances is to reconcile the sometimes competing requirements to obtain the best forensic evidence possible with as little danger to investigators and the public, while doing so as quickly as possible so as to cause the least interference with the legitimate activities of people who live and work in the vicinity. The primary duty of the police in these situations is to ensure the right to life of everyone within the danger zone. Moreover, the safety and security of the police and emergency services personnel working at such sites is also a human right protected by international law. Police officers and members of emergency services should enjoy just and favourable conditions of work that ensure their safety and protect their physical and psychological health. Preventive measures can be taken in this regard in order to mitigate the hazards related to their occupations. In practice, these rights can be protected in the following ways: • A security cordon should be placed around the scene, and should be positioned and resourced so as to prevent any unauthorized entry and ensure the safety of the public from the danger of falling masonry or other hazards; • Crime scene investigators and others working within the cordon should be equipped with suitable protective clothing, especially headgear and footwear; and • Everyone working within the security cordon and the crime scene should be appropriately trained to carry out their roles and be thoroughly briefed as to the potential dangers. The responsibility of senior officers in this respect is identical to that discussed in the context of the use of force in section 3.2 of this manual. The positioning of the security cordon and its duration need to be carefully considered, exercising tact and diplomacy. Where an explosion or other major incident has affected a large area of a city, an extended cordon, maintained for a considerable length of time while police search for forensic evidence, may