More details are in John 18:
2 Now Judas, who was delivering Him up, also knew the place, because Jesus often gathered together there with His disciples. 3Therefore Judas, having procured the cohort and officers from the chief priests and from the Pharisees, comes there with lanterns and torches and weapons.
St. John uses the technical word for the Roman cohort. It was the garrison band from Fort Antonia, at the north-east corner of the Temple. This well-known "band" is mentioned again in the New Testament (in John 18:12; Matthew 27:27; Mark 15:16; Acts 21:31). (Comp. Notes at these places.) The word occurs also in Acts 10:1 ("the Italian band") and Acts 27:1 ("Augustus' band"). ...
The band was Roman; the "officers" were the Temple servants, of whom we read in John 7:32; John 7:45. These were sent, here, as there, by the chief priests and Pharisees, with Judas for their guide, and their authority was supported by the civil power.
Judas was there to identify/point out Jesus with a kiss.
but Jesus asked him, "Judas, are you betraying the Son of Man with a kiss?"
The officers were temple guards. They were sent to arrest Jesus once before but failed.
The Pharisees heard the crowd whispering such things about him. Then the chief priests and the Pharisees sent temple guards to arrest him.
This time, they were backed up by the Roman soldiers. In case people like Peter would fight against the arrest, they had the overwhelming force on their side. The two militias worked together.
Then the detachment of soldiers with its commander and the Jewish officials arrested Jesus. They bound him.
First, they took Jesus to the Sanhedrin.
They took Jesus to the high priest, and all the chief priests, the elders and the teachers of the law came together.
Later they took Jesus to Pilate.
Then the governor's soldiers took Jesus into the Praetorium and gathered the whole company of soldiers around him.
So, yeah, they were very organized this time and planned it with military precision.