A.T. Robertson Commentary Mark 14:60

"And the high priest stood up in the midst, and asked Jesus, saying, Answerest thou nothing? what is it which these witness against thee?" — Mark 14:60 (ASV)

Stood up in the midst (αναστας εις μεσον). Second aorist active participle. For greater solemnity he arose to make up by bluster the lack of evidence. The high priest stepped out into the midst as if to attack Jesus by vehement questions. See on Mt 26:59-68 for details here.