The Kitáb-i-Aqdas - The Most Holy Book
Index term: Murder
k19.
Ye have been forbidden to commit murder or adultery, or to engage in backbiting or calumny; shun ye, then, what hath been prohibited in the holy Books and Tablets.
k62.
Should anyone intentionally destroy a house by fire, him also shall ye burn; should anyone deliberately take another's life, him also shall ye put to death. Take ye hold of the precepts of God with all your strength and power, and abandon the ways of the ignorant. Should ye condemn the arsonist and the murderer to life imprisonment, it would be permissible according to the provisions of the Book. He, verily, hath power to ordain whatsoever He pleaseth.
k73.
Adorn yourselves with the raiment of goodly deeds. He whose deeds attain unto God's good pleasure is assuredly of the people of Bahá and is remembered before His throne. Assist ye the Lord of all creation with works of righteousness, and also through wisdom and utterance. Thus, indeed, have ye been commanded in most of the Tablets by Him Who is the All-Merciful. He, truly, is cognizant of what I say. Let none contend with another, and let no soul slay another; this, verily, is that which was forbidden you in a Book that hath lain concealed within the Tabernacle of glory. What! Would ye kill him whom God hath quickened, whom He hath endowed with spirit through a breath from Him? Grievous then would be your trespass before His throne! Fear God, and lift not the hand of injustice and oppression to destroy what He hath Himself raised up; nay, walk ye in the way of God, the True One. No sooner did the hosts of true knowledge appear, bearing the standards of Divine utterance, than the tribes of the religions were put to flight, save only those who willed to drink from the stream of everlasting life in a Paradise created by the breath of the All-Glorious.
n35.
Ye have been forbidden to commit murder
The prohibition against taking another's life is repeated by Bahá'u'lláh in paragraph 73 of the Kitáb-i-Aqdas. Penalties are prescribed for premeditated murder (see note 86). In the case of manslaughter, it is necessary to pay a specified indemnity to the family of the deceased (see Kitáb-i-Aqdas, 188).
n86.
Should anyone intentionally destroy a house by fire, him also shall ye burn; should anyone deliberately take another's life, him also shall ye put to death.
The law of Bahá'u'lláh prescribes the death penalty for murder and arson, with the alternative of life imprisonment (see note 87).
In His Tablets 'Abdu'l-Bahá explains the difference between revenge and punishment. He affirms that individuals do not have the right to take revenge, that revenge is despised in the eyes of God, and that the motive for punishment is not vengeance, but the imposition of a penalty for the committed offence. In Some Answered Questions, He confirms that it is the right of society to impose punishments on criminals for the purpose of protecting its members and defending its existence.
With regard to this provision, Shoghi Effendi in a letter written on his behalf gives the following explanation:

In the Aqdas Bahá'u'lláh has given death as the penalty for murder. However, He has permitted life imprisonment as an alternative. Both practices would be in accordance with His Laws. Some of us may not be able to grasp the wisdom of this when it disagrees with our own limited vision; but we must accept it, knowing His Wisdom, His Mercy and His Justice are perfect and for the salvation of the entire world. If a man were falsely condemned to die, can we not believe Almighty God would compensate him a thousandfold, in the next world, for this human injustice? You cannot give up a salutary law just because on rare occasions the innocent may be punished.

The details of the Bahá'í law of punishment for murder and arson, a law designed for a future state of society, were not specified by Bahá'u'lláh. The various details of the law, such as degrees of offence, whether extenuating circumstances are to be taken into account, and which of the two prescribed punishments is to be the norm are left to the Universal House of Justice to decide in light of prevailing conditions when the law is to be in operation. The manner in which the punishment is to be carried out is also left to the Universal House of Justice to decide.
In relation to arson, this depends on what "house" is burned. There is obviously a tremendous difference in the degree of offence between the person who burns down an empty warehouse and one who sets fire to a school full of children.
n87.
Should ye condemn the arsonist and the murderer to life imprisonment, it would be permissible according to the provisions of the Book.
Shoghi Effendi, in response to a question about this verse of the Aqdas, affirmed that while capital punishment is permitted, an alternative, "life imprisonment", has been provided "whereby the rigours of such a condemnation can be seriously mitigated". He states that "Bahá'u'lláh has given us a choice and has, therefore, left us free to use our own discretion within certain limitations imposed by His law". In the absence of specific guidance concerning the application of this aspect of Bahá'í law, it remains for the Universal House of Justice to legislate on the matter in the future.
n190.
O source of perversion!
This is a reference to Mírzá Yahyá, known as Subh-i-Azal (Morning of Eternity), a younger half-brother of Bahá'u'lláh, who arose against Him and opposed His Cause. Mírzá Yahyá was nominated by the Báb to serve as a figure-head for the Bábí community pending the imminent manifestation of the Promised One. At the instigation of Siyyid Muhammad-i-Isfahání (see note 192), Mírzá Yahyá betrayed the trust of the Báb, claimed to be His successor, and intrigued against Bahá'u'lláh, even attempting to have Him murdered. When Bahá'u'lláh formally declared His Mission to him in Adrianople, Mírzá Yahyá responded by going to the length of putting forward his own claim to be the recipient of an independent Revelation. His pretensions were eventually rejected by all but a few, who became known as Azalís (see note 177). He is described by Shoghi Effendi as the "Arch-Breaker of the Covenant of the Báb" (see God Passes By, chapter X).
n192.
God hath laid hold on him who led thee astray.
A reference to Siyyid Muhammad-i-Isfahání, who is described by Shoghi Effendi as the "Antichrist of the Bahá'í Revelation". He was a man of corrupt character and great personal ambition who induced Mírzá Yahyá to oppose Bahá'u'lláh and to claim prophethood for himself (see note 190). Although he was an adherent of Mírzá Yahyá, Siyyid Muhammad was exiled with Bahá'u'lláh to 'Akká. He continued to agitate and plot against Bahá'u'lláh. In describing the circumstances of his death, Shoghi Effendi has written in God Passes By:

A fresh danger now clearly threatened the life of Bahá'u'lláh. Though He Himself had stringently forbidden His followers, on several occasions, both verbally and in writing, any retaliatory acts against their tormentors, and had even sent back to Beirut an irresponsible Arab convert, who had meditated avenging the wrongs suffered by his beloved Leader, seven of the companions clandestinely sought out and slew three of their persecutors, among whom were Siyyid Muhammad and Áqá Ján.
The consternation that seized an already oppressed community was indescribable. Bahá'u'lláh's indignation knew no bounds. "Were We", He thus voices His emotions, in a Tablet revealed shortly after this act had been committed, "to make mention of what befell Us, the heavens would be rent asunder and the mountains would crumble." "My captivity", He wrote on another occasion, "cannot harm Me. That which can harm Me is the conduct of those who love Me, who claim to be related to Me, and yet perpetrate what causeth My heart and My pen to groan."