Harlan F. Stone,
Beazell v. Ohio ex rel. Chatfield…
“ But it is now well settled that statutory changes in the mode of trial or the rules of evidence, which do not deprive the accused of a defense and which operate only in a limited and unsubstantial manner to his disadvantage, are not prohibited. A statute which, after indictment, enlarges the class of persons who may be witnesses at the trial, by removing the disqualification of persons convicted of felony, is not an ex post facto law. ”
