CONSTITUTION OF BOTSWANA
CHAPTER II - Protection of Fundamental Rights and Freedoms of the Individual (ss 3-19)
10. Provisions to secure protection of law
(2) Every person who is charged with a criminal offence-
(I) shall be permitted to have without payment the assistance of an interpreter if he or she cannot understand the language used at the trial of the charge,
Rights during trial - interpretation and translation
EDIT.