3. The right to an independent and impartial tribunal 31. States parties should strive firmly to ensure a lack of any racial or xenophobic prejudice on the part of judges, jury members and other judicial personnel. 32. They should prevent all direct influence by pressure groups, ideologies, religions and churches on the functioning of the system of justice and on the decisions of judges, which may have a discriminatory effect on certain groups. 33. States parties may, in this regard, take into account the Bangalore Principles of Judicial Conduct adopted in 2002 (E/CN.4/2003/65, annex), which recommend in particular that:  Judges should be aware of the diversity of society and differences linked with background, in particular racial origins;  They should not, by words or conduct, manifest any bias towards persons or groups on the grounds of their racial or other origin;  They should carry out their duties with appropriate consideration for all persons, such as the parties, witnesses, lawyers, court staff and their colleagues, without unjustified differentiation; and  They should oppose the manifestation of prejudice by the persons under their direction and by lawyers or their adoption of discriminatory behaviour towards a person or group on the basis of their colour, racial, national, religious or sexual origin, or on other irrelevant grounds. D. Guarantee of fair punishment 34. In this regard, States should ensure that the courts do not apply harsher punishments solely because of an accused person’s membership of a specific racial or ethnic group. 35. Special attention should be paid in this regard to the system of minimum punishments and obligatory detention applicable to certain offences and to capital punishment in countries which have not abolished it, bearing in mind reports that this punishment is imposed and carried out more frequently against persons belonging to specific racial or ethnic groups. 36. In the case of persons belonging to indigenous peoples, States parties should give preference to alternatives to imprisonment and to other forms of punishment that are better adapted to their legal system, bearing in mind in particular International Labour Organization Convention No. 169 concerning Indigenous and Tribal Peoples in Independent Countries. 37. Punishments targeted exclusively at non-nationals that are additional to punishments under ordinary law, such as deportation, expulsion or banning from the country concerned, should be imposed only in exceptional circumstances and in a proportionate manner, for serious reasons related to public order which are stipulated in the law, and should take into account the need to respect the private family life of those concerned and the international protection to which they are entitled. E. Execution of sentences 38. When persons belonging to the groups referred to in the last paragraph of the preamble are serving prison terms, the States parties should: 9