Question: What advice does the Talmud have for a prosecutor?
Answer: The Talmud’s statements about prosecution were made in the context of a legal system rather different from ours; they dealt with a judge who is arguing for conviction before his fellow-judges, not with a prosecuting attorney who is arguing before a court. A judge must try to determine the truth, and must take all the available information into account, even information that is not admissible as evidence; he must not suppress or ignore such information.
A classical quote on this subject can be found in the Talmud, Shevuos 30b: “How do we know that a judge must not defend his own view? Because it says ‘You shall distance yourself from falsehood.’ (Rashi: If he is judging a case, and in his heart he feels that he may be mistaken, he should not give arguments in support of his view because he is ashamed to retract it; rather, he should investigate all aspects in order to arrive at a true judgment.) And how do we know if a judge knows that a case is fraudulent (Rashi: He deduces from the words of the witnesses that their testimony is not true), he should not say ‘I will rule on this case, and the guilt will be on the witnesses’? Because it says ‘You shall distance yourself from falsehood.’” These statements are codified by the Rambam (Sanhedrin, Chs. 21-24) and the Shulchan Aruch (Choshen Mishpat, Chs. 15-17).