In Matthew 26:61, two witnesses came forward with similar testimony against Jesus, but Mark 14:55-59 explains that it did not meet the legal requirement for conviction. The Sanhedrin was forced by their own procedures to ask Jesus outright if He claimed to be the Son of God. Jesus confessed the crime (Matthew 26:63-66, Mark 14:61-65, Luke 22:70-71). By confessing, Jesus convicted Himself, and the trial went into the penalty phase.
The penalty for blasphemy was death, but since the Romans had taken away their authority to impose the death penalty, they had to refer Jesus to the Roman authorities. But Pilate declared that Jesus was not guilty of any crime against Roman law. (Matthew 27:23, Mark 15:14, Luke 23:13-16, John 18:38) In the end, Pilate bowed to pressure and consented to the crucifixion under protest. (Matt. 27:24)
Blasphemy means to speak evilly of God (to curse God). Again, I don't see where he confessed to this crime in there. Now, I'll grant that they convicted Him. But the point I was driving at was that He, in fact, did not violate their law in any way. As it says in Hebrews:
For we do not have a high priest who is unable to sympathize with our weaknesses, but one who has similarly been tested in every way, yet without sin.