Before a case reaches trial, parties engage in discovery, the pre-trial exchange of relevant information and evidence. Common discovery methods include interrogatories (written questions sent to the opposing party that must be answered under oath within a specified time), depositions (sworn, out-of-court testimony from witnesses recorded by a court reporter), requests for production of documents, and requests for admissions. Other tools support the gathering of evidence: a subpoena is a court-issued order commanding a person to testify (subpoena ad testificandum) or to produce documents (subpoena duces tecum), with non-compliance leading to contempt of court. An affidavit is a written statement of facts made voluntarily and confirmed by oath or affirmation, usable as evidence and exposing the maker to perjury charges if knowingly false.
Trials themselves follow established procedures designed to ensure fairness. Voir dire is the jury selection process in which attorneys and the judge question potential jurors to determine their suitability, with removal available through challenges for cause based on juror bias or through limited peremptory challenges that require no reason. A defendant may file a motion to dismiss, asking the court to throw out the plaintiff's case before trial on grounds such as lack of jurisdiction, failure to state a claim, or improper service of process. If the evidence presents no genuine dispute of material fact, either party may seek summary judgment, a ruling made without a full trial. At the outset of trial, a plaintiff must establish a prima facie case by presenting evidence sufficient to support each element of the claim, shifting the burden to the defendant to rebut it.
Different types of cases carry different standards of proof, reflecting the severity of what is at stake. The burden of proof is the obligation to prove allegations in a legal proceeding, borne by the prosecution in criminal cases and typically by the plaintiff in civil cases. Beyond a reasonable doubt is the highest standard, used in criminal cases, requiring the prosecution to prove each element so thoroughly that no reasonable person would doubt the defendant's guilt. In most civil cases, the lower preponderance of the evidence standard applies, meaning the plaintiff must show claims are more likely than not true, with a probability greater than fifty percent. Between these two standards lies clear and convincing evidence, used in some specialized civil proceedings. Hearsay, an out-of-court statement offered for the truth of the matter asserted, is generally inadmissible because the original speaker cannot be cross-examined, although numerous exceptions apply, including excited utterances, dying declarations, and business records.