7. Objection to proceedings.
It shall not be an objection to any proceedings taken against a person by virtue of the provisions of sections 6 and 7 that under the law in force at the time when and in the place where he is alleged to commit the act of which he was accused or of which he was convicted he could not have been punished therefor.
Non-retroactivity
Nullum crimen sine lege
Nulla poena sine lege
EDIT.