1. Contact a lawyer: If you are the defendant or the victim, you'd better contact a lawyer who is familiar with local laws, understand the specific circumstances of the case, and get advice and guidance on evidence.
2. Challenge the evidence: If there is something wrong with the evidence, you or your lawyer can challenge it to the court. For example, evidence is unreliable, illegally obtained, misunderstood or contradictory, which can be questioned. If the court accepts the query and thinks that the evidence is not credible, it can exclude the evidence.
3. Apply for evidence exclusion: If the evidence is obtained illegally, such as violating the search warrant, arrest warrant or search and seizure rules, you or your lawyer can apply to the court for evidence exclusion. If the court accepts your request, the evidence will not be used in the trial.
4. Seek expert advice: In some cases, the evidence may need to be interpreted by professional knowledge or technical means. For example, a DNA test or psychological evaluation may be required. You or your lawyer can ask the court to hire an expert to evaluate the evidence and question it on the basis of its evaluation report.