P.R. Laws Ap. tit. 34A, § II, Rule 170
When it is alleged as a cause why sentence should not be pronounced, that the defendant is not the person against whom the verdict was rendered or the judgment pronounced, or that the defendant was granted a pardon for the offense for which sentence is to be pronounced against him, the court shall, if necessary, postpone the pronouncement of sentence in order to receive the relevant evidence of said fact. If said evidence justifies the alleged cause, the defendant shall forthwith be released, unless he should remain under arrest to answer for other offenses. When the cause alleged is the prescription of the offense for which the defendant was declared guilty, once the said prescription is verified, the court shall order the dismissal of the information and the immediate release of the defendant.