What lies behind the situation is one fact : that the Jews (of that day) wanted Paul to die.
They had no good reason. There was no just cause. It is quite clear that, had they the power and authority to execute him, they would have done so, unjustly, with false witnesses.
But Rome was the occupying power and Rome did not permit the local authority to have the death sentence. Therefore the Jews had to cause enough fuss, raise enough disturbance, insinuate sufficient doubt, that the local authority must do something to quiten the situation.
In the midst of this, Paul appeals to Caesar since Paul is a Roman, having citizen rights from Tarsus. Paul was not willing to plead guilty, suffer a slight charge, a low-level sentence to make the whole thing go away.
Rather, he wishes to maintain his reputation and his own integrity and he wishes to have things done properly and judicially.
Therefore he forces the issue and appeals to Caesar.
And in the end, as we know from history, he was exonerated at his first trial.