CCPR/C/GC/36 38. Article 6 (2) also requires States parties to ensure that any death sentence would be “in accordance with the law in force at the time of the commission of the crime”. This application of the principle of legality complements and reaffirms the application of the principle of nulla poena sine lege found in article 15 (1) of the Covenant. As a result, the death penalty can never be imposed if it was not provided by law for the offence at the time of its commission. Nor can the imposition of the death penalty be based on vaguely defined criminal provisions,162 whose application to the convicted individual depend on subjective or discretionary considerations,163 the application of which is not reasonably foreseeable.164 On the other hand, the abolition of the death penalty should apply retroactively to individuals charged or convicted of a capital offence in accordance with the retroactive leniency (lex mitior) principle, which finds partial expression in the third sentence of article 15 (1), requiring States parties to grant offenders the benefit of lighter penalties adopted after the commission of the offence. The retroactive application of the abolition of the death penalty to all individuals charged or convicted of a capital crime also derives from the fact that the need for applying the death penalty cannot be justified once it has been abolished. 39. Article 6 (3) reminds all States parties that are also parties to the Convention on the Prevention and Punishment of the Crime of Genocide of their obligations to prevent and punish the crime of genocide, which include the obligation to prevent and punish all deprivations of life, which constitute part of a crime of genocide. Under no circumstances can the death penalty be imposed as part of a policy of genocide against members of a national, ethnic, racial or religious group. 40. States parties that have not abolished the death penalty must respect article 7 of the Covenant, which prohibits certain methods of execution. Failure to respect article 7 would inevitably render the execution arbitrary in nature and thus also in violation of article 6. The Committee has already opined that stoning, 165 injection of untested lethal drugs, 166 gas chambers,167 burning and burying alive168 and public executions169 are contrary to article 7. For similar reasons, other painful and humiliating methods of execution are also unlawful under the Covenant. Failure to provide individuals on death row with timely notification about the date of their execution constitutes, as a rule, a form of ill-treatment, which renders the subsequent execution contrary to article 7 of the Covenant. 170 Extreme delays in the implementation of a death penalty sentence that exceed any reasonable period of time necessary to exhaust all legal remedies171 may also entail the violation of article 7 of the Covenant, especially when the long time on death row exposes sentenced persons to harsh172 or stressful conditions, including solitary confinement,173 and when sentenced persons are particularly vulnerable due to factors such as age, health or mental state.174 41. Violation of the fair trial guarantees provided for in article 14 of the Covenant in proceedings resulting in the imposition of the death penalty would render the sentence arbitrary in nature, and in violation of article 6 of the Covenant.175 Such violations might involve the use of forced confessions;176 the inability of the accused to question relevant witnesses;177 lack of effective representation involving confidential attorney-client meetings during all stages of the criminal proceedings, 178 including criminal interrogation, 179 preliminary hearings,180 trial181 and appeal;182 failure to respect the presumption of innocence, which may manifest itself in the accused being placed in a cage or being handcuffed during the trial;183 lack of an effective right of appeal;184 lack of adequate time and facilities for the preparation of the defence, including the inability to access legal documents essential for conducting the legal defence or appeal, such as official prosecutorial applications to the court,185 the court’s judgment186 or the trial transcript; lack of suitable interpretation;187 failure to provide accessible documents and procedural accommodation for persons with disabilities; excessive and unjustified delays in the trial188 or the appeal process;189 and general lack of fairness of the criminal process, 190 or lack of independence or impartiality of the trial or appeal court. 42. Other serious procedural flaws not explicitly covered by article 14 of the Covenant may nonetheless render the imposition of the death penalty contrary to article 6. For example, a failure to promptly inform detained foreign nationals of their right to consular notification pursuant to the Vienna Convention on Consular Relations, resulting in the imposition of the death penalty,191 and failure to afford individuals about to be deported to a country in which 9