A culprit, under English law properly the prisoner at the bar, is one accused of a crime.
On the prisoner at the bar pleading not guilty, the clerk of the crown answered culpable, and states that he was ready ("prest") to join issue.
prist" were then entered on the roll, showing that issue had been joined.
in answer to a plea of "not guilty," is first found in the trial for murder of the 7th Earl of Pembroke in 1678.
[1] Under current criminal law, the preferred term is defendant.