The burden of proof in all legal cases should always rest with the party bringing the accusation. However, both sides should be required to do everything they can to both prove their own respective positions and to help clarify and promote an understanding of the circumstances surrounding a dispute. It should be regarded as criminal behavior to just sit on potentially relevant information or significant evidence that may help in arriving at a just decision, even if this evidence is held by the defense (since it is usually the defense that sits on evidence) and even if it may end up hurting the defense’s case. All parties have an obligation to help each other arrive at the truth.
It is not the prosecutor’s job to convict the defendant and it is not the defense attorney’s job to defend their client. It is everyone’s job to make sure that the truth prevails, which means that it is everyone’s obligation to introduce all relevant evidence that has a bearing on the case. It is everyone’s job to strive for the most efficient path towards a just resolution of the matter.