Like carbon dating, this can not be conclusively used to confirm identity. Rather it can be used to exclude other possible identities. In the case reported here for instance, carbon dating excludes the possibility that the individual buried in the tomb reported to be St. Paul's dates from a later time period. This therefore, is consistent with the hypothesis that the body is that of St. Paul but does not definitively prove it.
Definitive proof is a far more rigorous and difficult proposition. It would require a knowledge of St. Paul's family tree and extant DNA samples from known relatives. Alternatively, forensic evidence in the remains for some pathology from which St.Paul was known to suffer, would also be convincing.
I could be wrong but I thought he was
a Roman (that is an proto-Italian).