Key paragraph(s) can be found below the document.Montero-Aranguren
67. The use of force by governmental security forces must be grounded on the existence of exceptional circumstances and should be planned and proportionally limited by the government authorities. In this aspect, the Court has established that force or coercive means can only be used once all other methods of control have been exhausted and failed.
68. The use of firearms and lethal force against people by law enforcement officers -which must be generally forbidden- is only justified in even more extraordinary cases. The exceptional circumstances under which firearms and lethal force may be used shall be determined by the law and restrictively construed, so that they are used to the minimum extent possible in all cases, but never exceeding that use “absolutely necessary” in relation to the force or threat to be repealed. When excessive force is used, any deprivation of life is arbitrary.
83. […] any deficiency or fault in the investigation affecting the ability to determine the cause of death or to identify the actual perpetrators or masterminds of the crime will constitute failure to comply with the obligation to protect the right to life