Art. 855 Errors discovered after verdict or judgment of guilty; necessary allegations

If you find out about a mistake in your case after you've already been convicted, you can ask the judge for a new trial. But you can't just make a general complaint. You have to put your reasons in writing, and either you or your lawyer must sign them under oath, swearing they are true.

Your written request has to do two specific things. First, it must explain exactly what went wrong in your case. You can't be vague about it. You need to spell out the actual error or problem you discovered. Second, you have to show that you or your lawyer were paying attention and doing your job properly, but still couldn't have caught this problem before or during the trial. In other words, you can't use this rule for something you should have noticed earlier if you had been careful.

This rule exists so people can't wait until after a guilty verdict and then dig up minor issues to try to get a do-over. The court wants proof that the problem was real, specific, and truly impossible to catch earlier, even with careful effort. If you can't meet both of these requirements with sworn facts, the judge can deny your request for a new trial on this ground.