Norma relacionada
Switzerland
Practice Relating to Rule 101. The Principle of Legality
Switzerland’s Military Criminal Code (1927), taking into account amendments entered into force up to 2011, which also contains a chapter on war crimes, states in a part on general provisions: “A sentence or measure must only be pronounced for an act expressly declared to be an offence by the law.” 
Switzerland, Military Criminal Code, 1927, taking into account amendments entered into force up to 2011, Article 1.
Switzerland’s Penal Code (1937), taking into account amendments entered into force up to 2011, which also contains a chapter on war crimes, states in the book on general provisions: “A sentence or measure must only be pronounced for an act expressly declared to be an offence by the law.” 
Switzerland, Penal Code, 1937, taking into account amendments entered into force up to 2011, Article 1.
In 2010, in its Report on IHL and Current Armed Conflicts, Switzerland’s Federal Council stated:
3.4 [Increasing use] of anti-guerrilla tactics
Apart from the direct fight against insurgents, international humanitarian law also addresses other anti-guerrilla tactics. … If members of militias or opposition groups fall into the hands of the government they benefit from the protection of art. 75 of [the 1977] Additional Protocol I as well as that of art. 3 common to the [1949] Geneva Conventions. 
Switzerland, Federal Council, Report on IHL and Current Armed Conflicts, 17 September 2010, Section 3.4, p. 15.
[footnotes in original omitted]