Related Rule
Ireland
Practice Relating to Rule 89. Violence to Life
Ireland’s Basic LOAC Guide (2005) states: “The following acts are specified as grave breaches under the convention for the treatment of PWs [prisoners of war] [1949 Geneva Convention III]: - wilful killing …”. 
Ireland, Basic Guide to the Law of Armed Conflict, TP/TRG/01-2005, Director of Defence Forces Training, Department of Defence, July 2005, p. 10.
The manual further states that “wilful killing” is a grave breach of the 1949 Geneva Convention IV relating to the treatment of civilians. 
Ireland, Basic Guide to the Law of Armed Conflict, TP/TRG/01-2005, Director of Defence Forces Training, Department of Defence, July 2005, p. 12.
The manual also provides a list of “Soldiers Rules”, one of which is: “Do not … kill … prisoners of war.” 
Ireland, Basic Guide to the Law of Armed Conflict, TP/TRG/01-2005, Director of Defence Forces Training, Department of Defence, July 2005, p. 13.
Ireland’s Geneva Conventions Act (1962), as amended in 1998, provides that grave breaches of the 1949 Geneva Conventions are punishable offences. 
Ireland, Geneva Conventions Act, 1962, as amended in 1998, Section 3(1).
In addition, any “minor breach” of the 1949 Geneva Conventions, including violations of common Article 3, of Article 12 of Geneva Convention I, of Article 12 of Geneva Convention II, of Article 13 of Geneva Convention III, of Articles 27 and 32 of Geneva Convention IV, and of the 1977 Additional Protocol I, including violations of Article 75(2)(a), as well as any “contravention” of the 1977 Additional Protocol II, including violations of Article 4(2)(a), are also punishable offences. 
Ireland, Geneva Conventions Act, 1962, as amended in 1998, Section 4(1) and (4).