Adam Clarke on Acts 28:17

Paul called the chief of the Jews together - We have already seen, in Act 18:2, that Claudius had commanded all Jews to depart from Rome; see the note there: but it seems they were permitted to return very soon; and, from this verse, it appears that there were then chiefs, probably of synagogues, dwelling at Rome.

I have committed nothing - Lest they should have heard and received malicious reports against him, he thought it best to state his own case.