The trial of Jesus Christ was without legal precedent. He was convicted and executed even though Pilate found Him innocent! Let's briefly notice the twelve outstanding reasons why the arrest, trial and conviction of Jesus were illegal.
1. There was no legal basis for Jesus' arrest because no one had presented a formal charge of any crime; He simply was taken. Moreover, those who went with Judas to have Jesus arrested included the priests and elders--His judges (Luke 22:52)--among whom were the ones who bribed Judas!
2. Jesus was subjected to a secret preliminary examination at night (John 18:12-14, 19-23). Jewish law permitted only daylight proceedings.
3. The indictment against Jesus was illegal because the judges themselves brought up the charge without any prior testimony by witnesses. The Jewish court (the Sanhedrin) by law was not allowed to originate charges.
4. The court illegally proceeded to hold its trial of Jesus before sunrise so no one would be available to testify on His behalf.
5. The trial began on a day before an annual Sabbath (John 18:28), even though Jewish law did not permit the trial of a capital offense to begin on a Friday or the day before an annual Sabbath. Jesus was arrested and tried on the 14th of Abib, the day before the first annual Sabbath of the Feast of Unleavened Bread.
6. Jesus' trial was concluded in one day. Jewish law says: "If a sentence of death is to be pronounced, it [a criminal case] cannot be concluded before the following day" (Mishna, "Sanhedrin" IV, 1). This was to allow sufficient opportunity for any witnesses in support of the accused to present themselves. Jesus' trial was conducted in private and completed in less than nine hours!
7. Two false witnesses charged Jesus with saying He would destroy the temple made with hands (Mark 14:58); yet He was condemned by the court on another false charge--that of blasphemy. He was condemned on His own testimony (Luke 22:67-71). But according to Jewish law, a person could not be condemned on his own testimony.
8. The merits of Jesus' defense were not considered. Despite Deuteronomy 13:14, the high priest did not "inquire, and make search, and ask diligently" to see whether Jesus' statement was blasphemous. The law in the Mishna says: "The judges shall weigh the matter in the sincerity of their conscience" ("Sanhedrin" IV, 5). Instead, the court pronounced sentence instantly and unanimously!
9. Those who would have voted against condemnation were not at Jesus' trial. Joseph of Arimathaea was a member of the court, yet he was not there (Luke 23:50-51). Jesus' opponents had made sure that only those who hated Him would be there.
10. The sentence was pronounced in a place forbidden by law. The trial took place at the high priest's house (Luke 22:54). According to the law, a death sentence could be pronounced only in the court's appointed place.
11. Most of the judges were legally disqualified to try Jesus. Some had bought their way into office, according to Josephus. Also, since they were known enemies of Jesus, Jewish law required that they disqualify themselves so He could be tried by impartial judges.
12. The court illegally switched the charges from blasphemy to treason before Pilate. Jesus' opponents wanted Him killed, but they did not want to do it themselves. So they charged Him with treason (Luke 23:2)--a Roman crime--so the Romans would be responsible for His death. No evidence was presented (John 18:29-30). Pilate, after a brief interview, saw that Jesus was not guilty (John 18:38, 19; Matt. 27:18). Fearing the crowd, however, he allowed the crucifixion of an innocent man. Pilate did not even pronounce Him guilty; he merely turned Him over to the soldiers.
What a mockery of justice this trial was! All this illegality, in addition to His crucifixion, Jesus willingly suffered to pay the penalty of our sins in our stead!
Source for this page: http://www.biblestudy.org/basicart/why-was-the-arrest-trial-conviction-of-jesus-illegal.html