the accused finds apparent support in the general language used in some opinions. Mr. Justice Chase, in his classification of ex post facto laws in Calder v. Bull, 3 Dall. 386, 390 [1:648,650] includes "every law that alters the legal rules of evidence, and receives less or different testimony than the law required at the time of the commission of the offense in order to convict the of fender." In Kring v. Missouri, 107 U. S. 221, 228, 232, 235 [27:506.509,510,511), the question arose as to the validity of a statute of Missouri under which the accused was found guilty of the crime of murder in the first degree and sentenced to be hung. That case was tried several times, and was three times in the supreme court of the state. At the trial immediately preceding the last one Kring was allowed to plead guilty of murder in the second degree. The plea was accepted, and he was sentenced to imprisonment in the penitentiary for the term of twenty-five years. Having understood that, upon this plea, he was to be sentenced to imprisonment for only ten years, he prosecuted an appeal, which resulted in a reversal of the judgment. At the last trial the court set aside the plea of guilty of murder in the second degree the accused having refused to withdraw it-and, against his objection, ordered a plea of not guilty to be entered in his behalf. Under the latter plea he was tried, convicted, and sentenced to be hanged. By the law of Missouri at the time of the commission of Kring's of fense, his conviction and sentence under the plea of guilty of murder in the second degree was an absolute acquittal of the charge of murder in the first degree. But that law having been changed before the final trial occurred, Kring contended that the last stat[383]ute, *if applied to his case, would be within the prohibition of ex post facto laws. And that view was sustained by this court, four of its members dissenting. In the opinion of the court in Kring's Case reference was made to the opinion of Mr. Justice Chase in Calder v. Bull, and also to the charge of the court to the jury in United States v. Hall, 2 Wash. C. C. 366, 373. In the latter case Mr. Justice Wash ington said: "An ex post facto law is one which, in its operation, makes that criminal or penal which was not so at the time the action was performed; or which increases the punishment; or, in short, which, in relation to the offense or its consequences, alters the situation of a party to his disadvantage." He added: "If the enforcing law applies to this case, there can be no doubt that, so far as it takes away or impairs the defense which the law had provided the defendant at the time when the condition of this bond became forfeited, it is ex post facto and inoperative." Considering the suggestion that the Missouri statute under which Kring was convicted only regulated procedure, Mr. Justice Miller, speaking for this court, said: "Can any substantial right which the law gave the defendant at the time to which his guilt relates be taken away from him by ex post facto legislation, because, in the use A careful examination of the opinion in This general subject was considered in Hopt v. Utah, 110 U. S. 574, 588.589 [28: 262, 268]. Hopt was indicted, tried, and convicted of murder in the territory of Utah, the punishment therefor being death. At the time of the commission of the offense it was the law of Utah that no person convicted of a felony could be a witness in a criminal case. After the date of the alleged offense, and prior to the trial of the case, an act was passed removing the disqualification as witnesses of persons who have been convicted of felonies. And the point was made that the statute, in its application to Hopt's case, was ex post facto. This court said: "The provision of the Constitution which prohibits the states from passing ex post facto laws was examined in Kring v. Missouri, 107 U. S. 221 [27:506]. The whole subject was there fully and carefully considered. The court, in view of the adjudged cases, as well as upon principle, held that a provision of the Constitution of Missouri denying to the prisoner, charged with murder in the first degree, the benefit of the law as it was at the commission of the offense-under which a conviction of murder in the second degree was an acquittal of murder in the first degree, even though such judgment of conviction was subsequently reversed-was in conflict with the Constitution of the United States. That decision proceeded upon the ground that the state Constitution deprived the accused of a substantial right which the law gave him when the offense was add: "Of course, a statute is not of that committed, and therefore, in its application to class unless it materially impairs the right of that offense and its consequences, altered the the accused to have the question of his guilt situation of the party to his disadvantage. [385]By the law as established when the offense was committed, Kring could not have been punished with death after his conviction of murder in the second degree, whereas, by the abrogation of that law by the constitutional provision subsequently adopted, he could thereafter be tried and convicted of murder determined according to the law as it was when the offense was committed. And, there fore, it is well settled that the accused is not entitled of right to be tried in the exact mode, in all respects, that may be prescribed for the trial of criminal cases at the time of the commission of the offense charged against him. Cooley in his Treatise on Constitutional in the first degree, and subjected to the pun- Limitations, after referring to some of the ishment of death. Thus the judgment of con- adjudged cases relating to ex post facto laws, viction of murder in the second degree was says: 'But, so far as mere modes of proceddeprived of all force as evidence to establish ure are concerned, a party has no more right, his absolute immunity thereafter from pun- in a criminal than in a civil action, ishment for murder in the first degree. to insist that his case shall be disposed of us. This was held to be the deprivation of a sub- under the law in force when the act to be in vestigated is charged to have taken place. Remedies must always be under the control of the legislature, and it would create endless coniusion in legal legal proceedings if every case was to be conducted only in accordance with the rules of practice and heard only by the courts in existence when its facts arose. legislature may abolish courts and create new ones, and it may prescribe altogether different modes of procedure in its discretion though it cannot lawfully, we think, in so The nor provide a greater punishment therefor doing, dispense with any of those substantial than was prescribed at the time of its com- protections with which the existing law surmission; nor do they alter the degree or lessen rounds the person accused of crime." Chap. the amount or measure, of the proof which 9, *272. was made necessary to conviction when the Applying the principles announced in crime was committed." The court added: former cases-without attaching undue "The crime for which the present defendant weight to general expressions in them that go was indicted, the punishment prescribed beyond the questions necessary to be detherefor, and the quantity or the degree of termined-we adjudge that the statute of proof necessary to establish his guilt, all re- Missouri relating to the comparison of writ [387] mained unaffected by the subsequent statute. Any statutory alteration of the legal rules of evidence which would authorize conviction upon less proof, in amount or degree, thàn was required when the offense was committed, might, in respect of that offense, be obnoxious to the constitutional inhibition upon ex post facto laws. But alterations which do not increase the punishment, nor change the ingredients of the offense, or the ultimate facts necessary to establish guilt, but-leaving untouched the nature of the crime and the amount or degree of proof essential to conviction-only remove existing restrictions upon the competency of certain classes of persons as witnesses, relate to modes of procedure only, in which no one can be said to have a vested right, and which the [386]*state, upon grounds of public policy, may regulate at its pleasure. Such regulations of the mode in which the facts constituting guilt may be placed before the jury, can be made applicable to prosecutions or trials thereafter had, without reference to the date of the commission of the offense charged." At the present term, in Thompson v. Utah, 170 U. S. 343 [42: 1061], this court observed, ings is not ex post facto when applied to prosecutions for crimes committed prior to its passage. If persons excluded, upon grounds of public policy at the time of the commission of an offense, from testifying as witnesses for or against the accused, may, in virtue of a statute, become competent to testify, we cannot perceive any ground upon which to hold a statute to be ex post facto which does nothing more than admit evidence of a particular kind in a criminal case upon an issue of fact which was not admissible under the rules of evidence as enforced by judicial de cisions at the time the offense was committed. The Missouri statute, when applied to this case, did not enlarge the punishment to which the accused was liable when his crime was committed, nor make any act involved in his offense criminal that was not criminal at the time he committed the murder of which he was found guilty. It did not change the quality or degree of his offense. Nor can the new rule introduced by it be characterized as unreasonable certainly not so unreasonable as materially to affect the substantial rights of one put on trial for crime. The statute did not require "less generally, that a statute is ex post facto proof, in amount or degree," than was rewhich, by its necessary operation and in quired at the time of the commission of the its relation to the offense or its con-crime charged upon him. It left unimpaired sequences, alters the situation of the accused the right of the jury to determine the suf to his disadvantage. But it took care to ficiency or effect of the evidence declared to |