The prohibition against retrial, also known as double jeopardy, is a legal principle that prevents an individual from being tried again for the same crime after either an acquittal or a conviction. This concept is rooted in the idea of legal finality and protecting individuals from the psychological and financial burdens associated with repeated trials for the same offense. It serves to uphold the integrity of the legal system by ensuring that once a verdict is reached, it cannot be revisited in court for the same charges.