Marriage Before Repenting For Fornication
There’s no gauge available to know of a person’s repentance state at a state level. Unless one is covicted of fornication at a state level, no one has a right to declare other person guilty of this crime and hence invalidating his Nikah based on his lack of repentance. Therefore, in such a case, the matter rests between the person and the God. If he didn’t repent sincerely then he’d have to be accountable to God on the day of judgement.