Did all of Jesus' arrest and mock trial occur before dawn?
Yes. The arrest began around midnight, possibly a little before, and the whole process of His arrest and mock trial took place before the early light of dawn. Nighttime was chosen, as totalitarian governments typically do, to make it a traumatic event.
Les explains that the human race hasn't changed: totalitarian governments typically arrest people at night, around 2 or 3 a.m., because it is a mental and traumatic thing. He notes that the same pattern holds in Jesus' arrest. Evidently it was right around midnight, perhaps a little before, and everything in the whole process of His arrest and mock trial took place before the early light of dawn. The first sign of His arrest in the garden was probably around midnight. Judas betrayed Him and led the soldiers, and though Jesus was meek and compassionate, they brought at least a hundred soldiers.