A/HRC/34/54/Add.3 isolation of individuals who are confined in their cells for 22 to 24 hours a day. He observed that while solitary confinement for short periods of time may be justified under certain circumstances, with adequate and effective safeguards in place, the use of prolonged (in excess of 15 days) or indefinite solitary confinement may never constitute a legitimate instrument of the State, as it may cause severe mental and physical pain or suffering, a point that has been reiterated in paragraph 28 of the General Assembly Resolution 68/156. Prolonged or indefinite solitary confinement runs afoul of the absolute prohibition of torture and other cruel, inhuman or degrading treatment or punishment. Due to the prisoner’s lack of communication, as well as the lack of witnesses inside the prison, solitary confinement may also give rise to other acts of torture or ill-treatment. Furthermore, concerning the medical treatment provided by the complainants, the Special Rapporteur highlights that the U.N. Standard Minimum Rules for the Treatment of Prisoners (“Mandela Rules”) establish that “Prisoners who require specialized treatment or surgery shall be transferred to specialized institutions or to civil hospitals” (Rule 27(1)). 232. The Special Rapporteur notes with approval the commutation of one of the complainant’s sentences from death to a lesser sentence. Nonetheless, the Special Rapporteur strongly urges the Government to fully comply with its obligations under the ICCPR, and customary international law, to investigate, prosecute and punish all acts of torture and other cruel, inhuman or degrading treatment or punishment, as codified, inter alia, in the Convention against Torture (CAT). The Rapporteur further calls upon the State to comply with the standards set out in the Mandela Rules as concerns the medical treatment provided the prisoners. JUA 20/01/2016 Case No. IRN 1/2016 State Reply: 07/07/16 Allegations concerning the sentence of execution by stoning or hanging of Mrs. Fariba Khalegi for the crime of adultery. 233. The Special Rapporteur thanks the Government of Iran for its reply, dated 7 July 2016, to the present communication. The Special Rapporteur acknowledges the account of the Government of Iran in response to the concerns, legal obligations, and questions raised in the initial communication. He welcomes the information provided by the Government, according to which the possibility exists for further review of Mrs. Khalegi’s case by the head of the Judiciary with the possibility of retrial and resentencing. However, in spite of the information supplied by the Government, its reply fails to inform the Special Rapporteur about the use of death penalty for offences that do not meet the threshold of the “most serious crimes” and the use of corporal punishment, such as stoning, as a method of execution. 234. In the absence of information to the contrary, the Special Rapporteur concludes that there is substance in the allegations presented in the initial communication, available via the link above, and that the Government, by using the death penalty for a crime such as adultery, and by leaving the possibility open for an execution by stoning, has failed to protect Mrs. Khalegi’s physical and mental integrity, and to protect her right to be free from torture or cruel, inhuman or degrading treatment or punishment, as provided by article 7 of the International Covenant on Civil and Political Rights and her right to life under article 6(2) of the same, as well as the customary international law prohibiting torture and cruel, inhuman, or degrading punishment. 235. For purposes of the imposition of capital punishment in retentionist States, the Special Rapporteur recalls that the notion of “most serious crimes” means offenses committed with intent to kill and that actually result in death. (A/HRC/4, para. 53 and CCPR General Comment 6) He highlights the report to the General Assembly in August 45