‘And when there arose a great dissension, the chief captain, fearing lest Paul should be torn in pieces by them, commanded the soldiers to go down and take him by force from among them, and bring him to the fortress.'
Indeed feelings now began to rise so high (and we really cannot blame Paul because they could not discuss reasonably together) that the chief captain who was observing the proceedings became alarmed and commanded that soldiers take him by force (the temple police may have tried to interfere) and convey him to the safety of the fortress.
He must have been in some despair. Here he was stuck with this prisoner, who was a Roman citizen and therefore difficult to deal with, and it was apparent that none of his opponents knew what to charge him with. He was having to hold him without charge and risk any consequences.