How can I write a court case convincingly?

You should take an afternoon or two and sit in on courtroom activities.

You need to do some research: Go to your nearest crown court and watch some cases. Find some introductory books about how criminal procedure works in the UK. To make your work convincing you need to know not just the relevant law and procedure, but also a lot of background: how lawyers behave in court, they different types of lawyer likely to be involved, how witnesses behave on the stand, all the goings on in the court building surrounding the trial. You should end up knowing more than you actually use in your work - this knowledge will help you to paint a convincing picture for your readers.

To give you a very brief outline of how criminal proceedings work:

1. Defendant is arrested, cautioned and taken to the police station where he is questioned. If D is sensible he'll have a lawyer - his own solicitor, a duty solicitor or perhaps even just an accredited police station representative - a paralegal of sorts

2. Defendant is charged, police decide whether to release him on police bail

3. Bail Hearing (if D is not released on police bail, he'll be brought before the Magistrates' Court to decide whether he should be bailed. Bail is normally granted, subject to various conditions)

4. Committal/Plea Before Venue (in some cases, the Magistrates' Court must decide whether the case will be tried there in the Crown court)

5. PCMH - Preliminary Case Management Hearing (in which lawyers and a judge deal with various pre-trial matters such as the admissibility of evidence, time necessary for trial etc)

6. Trial (the general order in a Crown Court trial would be: Opening statement for the Prosecution, Opening for the Defence, Prosecution calls all its evidence, Defence might then make a "half-time" submission that the prosecution's evidence is itself inadequate for a conviction. If that fails, the Defence will put on its case - witnesses etc. Prosecution will close, Defence will close, Judge will sum up and give the jury directions about the law. Jury will deliberate and delivery a verdict

7. If D is convicted, there will be a later hearing to sentence D.

Only write what you know about. I once read a novel by the father of a friend of mine which was based on a court case and I remember how full of errors it was when it came to criminal evidence and procedure. The mistakes simply screamed from the pages. Find some area in which you are competent -- or postpone writing a novel until you have learned something about life. A famous writer once told me that you should never write until you have something to say. Have you?