"Every human being has the inherent right to life. This right shall be protected by law. No man shall be deprived of his life arbitrarily."(International Covenant on Civil and Political Rights (ICCPR - 1966, Article 6.1)

"[The Death] penalty can only be carried out pursuant to a final judgement rendered by a competent court" (ICCPR (1966), Article 6.2)

"In the determination of any criminal charge against him, or of his rights and obligations in a suit at law, every man shall be entitled to a fair and public hearing by a competent, independent and impartial tribunal established by and under law. (ICCPR (1966), Article 14.1)"

Summary executions may even be illegal even during times of war, as the Second Additional Protocol of the Geneva Conventions (1977) states: "No sentence shall be passed and no penalty shall be executed on a person found guilty of an offence except pursuant to a conviction pronounced by a court offering the essential guarantees of independence and impartiality." (Second Protocol of the Geneva Conventions (1977) Art 6.2)