If somebody becomes non-grata person, then goes through witness protection program, can they visit the country under new identity?

If somebody becomes non grata person in some country, then for unrelated reasons goes through the witness protection program and obtains a new identity, can they visit that country under new identity and new documents? If said country does fingerprint check, are they gonna trust that, or just gonna be like "well, I guess that dude just happen to have the same fingerprints as that criminal we restricted access to the country 10 years ago" ?