All along Jesus had remained quiet because the chief priests and the whole council sought witnesses against Jesus to put him to death, and found none. Many gave false testimony against him, and their testimony didn't agree with each other. So Jesus could not answer to falsehood against him.

The only charge He was deemed guility in the eyes of the high priests was blasphemy. When He answered in affirmative to the high priest's question "Are you the Christ, the Son of the Blessed?" and Jesus answered, "I AM.

He gave further evidence that You will see the Son of Man sitting at the right hand of Power, and coming with the clouds of the sky."

To this the high priest tore his clothes, and judged Jesus to have comitted blasphemy and  therefore guility and they all condemned him to be worthy of death