The authority of the Legislature by granting full immunity from prosecution, to require a witness to testify, even to the commission of a crime by himself, where the facts concerning which the inquiry is made arise subsequent to the enactment of the law, is beyond question. The facts concerning which the relator refused to testify occurred prior to the enactment .of the law granting immunity from prosecution. Assuming that it was competent for the Legislature to grant immunity from prosecution as to crimes previously committed, and to compel a witness to disclose facts that may show or tend to show that he committed a crime before the enactment of the statute granting such immunity — questions not free from doubt — we come to the question as to whether the statute granting immunity and requiring witnesses to testify indicates a legislative intent that it should apply to past as well as to future crimes. The general rule is that a statute relating to evidence or matters of procedure merely affects pending actions and proceedings as well as *212those arising subsequently, but statutes affecting personal or property rights are given retrospective effect only when the legislative intent to make them retroactive is clearly manifested. The enactment of statutes affecting vested rights and of ex post facto laws is forbidden. (U. S. Const, art. 1, § 10, subd. 1; 14th amendt. § 1.) A person may do an act which all good citizens will agree deserves punishment, but if the act was not forbidden by law at the time' it was done, no statute can thereafter be legally enacted making it a punishable offense. Where the State adopts a new policy, ordinarily at least no attempt is made to apply a new rule to acts that transpired prior to the change in policy. The amendment to this statute makes a radical change in the law. The district attorney or one of his assistants, without the sanction of the court, may, by asking a single question on a preliminary examination, or before the grand jury, forever bar the prosecution of the. witness even for the most atrocious crimes.
. The language employed does not indicate a legislative intent to grant immunity for crimes already committed, or that the amendment should apply to inquiries concerning crimes committed before its enactment. If we were to take judicial notice of the origin of this amendment and of the public hearings thereon before the committees of the Legislature, it might be inferred that the author of the amendment and many legislators intended that it should have a retroactive effect, but the language employed does not expressly so declare, nor does it necessarily indicate such intent, and it may well be that many members of both branches of the Legislature voted for the measure in the belief that it would be given effect prospectively only. The question presented to us is neither one of evidence nor of procedure. Undoubtedly, neither party to a civil action or criminal prosecution could require the exclusion of evidence merely because at the time of the transaction under consideration such evidence would not be competent under the law as it then existed, but was rendered competent by subsequent statute. Here the objection is taken by the witness who claims that, inasmuch as he could not have been ■ required to answer these questions at the time to which the inquiries relate, it was not competent for the Legislature to thereafter enact a law granting him immunity and requiring him to disclose the facts, and that, even if competent, the act does not *213require and should not receive that construction. I am of opinion that the statute does not require a retroactive construction, and that its application should be limited to crimes committed after its enactment and to inquiries concerning such crimes.
These views lead to the conclusion that the writ should be sustained and the relator discharged.
Writ dismissed and proceedings affirmed, with costs.