John Calvin Commentary Acts 24:8

"[commanding his accusers to come before thee.] from whom thou wilt be able, by examining him thyself, to take knowledge of all these things whereof we accuse him." — Acts 24:8 (ASV)

Having made inquiry. A good request, that the governor does not pass sentence before he thoroughly examines and understands the matter, and that he does not condemn Paul before he is lawfully convicted. But how dare they include these conditions, since their own consciences accuse them of unjust dealing?

I answer that they had witnesses ready; and that they did not offer to prove the matter until they called them, although they had another purpose. For they hoped that Felix would be so persuaded by such impressive words that he would turn over to them the man whom they accused as a condemned man, whom they could then deal with as they pleased.

In summary, the fiercer they are against him, and the more they are puffed up with self-confidence, the more they think they will gain the upper hand by this method, because the accused party will have no permission granted to defend himself. Thus, false accusers boldly boast that their case is clear, so that they may blind the eyes of the judges.