Related Rule
Switzerland
Practice Relating to Rule 100. Fair Trial Guarantees
Section B. Trial by an independent, impartial and regularly constituted court
Switzerland’s Basic Military Manual (1987) provides: “Only an impartial and regularly constituted tribunal can judge and sentence an accused person.” 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 153, commentary.
The manual further states:
A person found guilty of a criminal offence committed in connection with the armed conflict shall be sentenced only in accordance with a judgment … This judgment shall be pronounced by an impartial and regularly constituted tribunal. 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 175.
According to the manual, it is a grave breach of the 1949 Geneva Conventions to deprive prisoners of war and civilians of “their right to be tried by an impartial and regularly constituted tribunal, in accordance with the conventions”. 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 192(b); see also § 193(2)(e).
Switzerland’s Military Criminal Code (1927), taking into account amendments entered into force up to 2011, states in a chapter entitled “War crimes”:
Art. 111
1 The penalty shall be a custodial sentence of not less than five years for any person who commits, in the context of an international armed conflict, a grave breach of the Geneva Conventions of 12 August 1949, namely one of the following acts against persons or objects protected under one of these Conventions:
g. denying a regular and fair judgment before the imposition or execution of a severe penalty.
2 Acts covered by paragraph 1 committed in the context of a non-international armed conflict are equivalent to grave breaches of international humanitarian law if they are directed against a person or object protected by that law. 
Switzerland, Military Criminal Code, 1927, taking into account amendments entered into force up to 2011, Articles 111(1)(g) and (2).
[footnote in original omitted]
Switzerland’s Penal Code (1937), taking into account amendments entered into force up to 2011, states under the title “War crimes”:
Art. 264c
1 The penalty shall be a custodial sentence of not less than five years for any person who commits, in the context of an international armed conflict, a grave breach of the Geneva Conventions of 12 August 1949, namely one of the following acts against persons or objects protected under one of these Conventions:
g. denying a regular and fair judgment before the imposition or execution of a severe penalty.
2 Acts covered by paragraph 1 committed in the context of a non-international armed conflict are equivalent to grave breaches of international humanitarian law if they are directed against a person or object protected by that law. 
Switzerland, Penal Code, 1937, taking into account amendments entered into force up to 2011, Article 264c (1)(g) and (2).
[footnote in original omitted]
Switzerland’s Criminal Procedure Code (2007), as amended to 2012, which regulates the prosecution and adjudication by the federal and cantonal criminal justice authorities of offences under federal law, including war crimes, states: “The criminal justice authorities are independent in applying the law and bound solely by the law.” 
Switzerland, Criminal Procedure Code, 2007, as amended to 2012, Article 4(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]