Your own legal team will lead you through justifications and explanations of each step through your investigation. Be prepared to stop at any point and answer 'Why' questions. You should prepare these questions and answers during trial preparation. Although tedious , you will have to provide very detailed explanations that satisfy the most skeptical listeners as to why you performed some action.
The real challenge comes during cross examination. Your own legal team questions you from the perspective that you performed your job appropriately and acquired evidence that proves facts. The opposing counsel will take the opposite approach. To the other side, the evidence does not prove the facts as they are presented or was not acquired properly. You will be asked to defend your actions at each step in the process. Be prepared to justify each action and explain precautions you took to preserve the evidence. Your investigation notebook will be invaluable. Make sure you keep your notebook up-to-date during an investigation and available during a trial.