Was Paul both a Jew and a Roman citizen?
Yes. Paul was both a Jew and a Roman citizen. The context describes him as a man who is not just a Jew, but also a Gentile by citizenship, specifically a Roman. This dual status fit his role as the Apostle of the Gentiles, chosen on Gentile ground.
Les explains that Paul had absolutely no connection with the twelve, who were Apostles of Israel chosen within Israel's borders. God chose and commissioned Paul as the Apostle of the Gentiles on Gentile ground. He took a man who was not just a Jew but also a Gentile by citizenship—a Roman. This is why Paul would never fit the qualifications Peter laid out in Acts 1 for Judas' replacement.