Some critics have pointed out that the text’s “We have neither received letters from Judea concerning you, nor have any of the brethren come here and reported or spoken anything bad about you” (Acts 28:21) is quite unbelievable. However, just as is usually the case, the whole truth cannot be derived from a cursory read of Luke’s account. His record needs to be compared with what we know of Paul’s time in the 1st century CE, and Luke’s account needs to be tested against what he says elsewhere in his thesis.
Luke tells us that Paul asked for a meeting the Jewish authorities in Rome and met with them only three days after his arrival there (Acts 28:17). Since we know that winter travel on the seas was too dangerous for normal sailing, and that Paul left Caesarea late in the year, it is not surprising to realize that he arrived in Rome before any communication could be arranged by Jerusalem with Jewish brethren in Rome. Also, since Paul’s appeal to Caesar came as a surprise to all in the home province of Judea, and the time of his departure was uncertain and then quite suddenly occurred, if correspondence from Jerusalem to the Roman Jews was on the ship with Paul, it and all the mail may very well have been cast overboard with the ship’s supplies to lighten its load (Acts 27:18-19).
One objection to this might be that correspondence could have been conducted over land during the winter and arrived in Rome before Paul could get there. This is true enough, but there are other matters to consider. We know that the Jewish authorities at Jerusalem knew they didn’t have a strong case against Paul, otherwise, why would they have conspired to kill him without the benefit of a trial (Acts 23:12-15; 25:3)? Therefore, the Jewish authorities would have had to regroup and decide whether or not they should even continue to pursue litigation against Paul at Rome, where they would have even less influence with Roman authorities than at home. At the very least they needed to decide how they would proceed against him, and that discussion may not have concluded in time for correspondence to reach Rome before Paul.
Therefore, whether the Jewish authorities at Jerusalem had sent correspondence to the Jews at Rome or not, there is a good explanation for believing that the Jewish authorities at Rome had heard nothing bad about Paul from Jerusalem by the time he had arrived and met with the Roman Jews.
Nevertheless, this does not mean the Roman Jews had heard nothing about Paul at all. They knew about the Messianic sect and, from their point of view, it had a negative reputation all over the Empire (Acts 28:22). This understanding may include the most recent expulsion of the Jews by Claudius Caesar a decade earlier in 49 CE over Jewish disturbances there concerning one called Chrestus (Christ). If they were at all familiar with the spread of the Jesus Movement in the Diaspora and had formulated opinions about its reputation, they undoubtedly had heard of the one who was largely responsible for its rapid spread among both Jews and gentiles.
Paul claimed he was innocent (Acts 28:17) of the charges laid against him, namely accusations that he was a renegade Jew. Rather he was found innocent by the Roman authorities (Acts 28:18), which was obvious in that he was placed under house arrest (Acts 28:16; cp. 28:30), showing Rome didn’t consider him a threat to Caesar or an evildoer. Rather Paul was forced to appeal to Caesar, because his own countrymen demanded his life. Thus, Luke again expresses Paul’s apparent innocence as a major theme in his thesis paralleling his plight with that of Jesus during his trials before his crucifixion.