I would start by planning it using a story mountain then putting each part into paragraphs to make it easier.
So the opening would be setting the scene (where the person is, what did they do to be there etc) the second part of build up would be what’s happening (whats happening before the trial) the 3rd part the problem would be the trial the 4th part the resolution would be are they found guilty? Or are they not guilty? Then the 5th part the ending would be what happed after the trial (did they go to prison? Were they let out without charge?) remember to include how they felt throughout the day (did they feel scared/nervous because of the trial, did they feel relieved because they were found not guilty)