How did Captain Preston involve the king in his testimony?

Captain Thomas Preston involved the king in his testimony by saying that the king had given him the authority to open fire against anyone whenever and wherever required.

Explanation:

During the trial that was separately run for Thomas Preston, he presented his testimony which attempted to indirectly blame the king for the massacre that happened. It is believed that President John Adams had instructed Captain Thomas Preston to involve the king himself in the Boston Massacre trial by including the king's name in his final testimony.