According to Mark, during a special holiday, the leader would let one person out of jail, and the people could choose who they wanted to go free. This was something that happened every year during the celebration time.
Mark 15:6: Now at [that] feast he released unto them one prisoner, whomsoever they desired.
The potential contradiction or inconsistency in Mark 15:6 could be related to the tradition of releasing a prisoner during the Passover feast. Some scholars debate whether there is historical evidence outside the Bible for this practice, leading to questions about its authenticity.