When two opposing parties are preparing to go to trial, the litigants may use two methods of obtaining important information about the facts surrounding the case: The interrogatory and the deposition. While both involve questioning of the opposing party as part of the pretrial discovery process, they serve entirely different functions. In fact, there is a fundamental difference between an interrogatory and a deposition.
An interrogatory, also known as a Request for Further Information, is a set of written questions posed to the opposite party that must be answered truthfully, in writing, under the penalty of perjury. In the U.S., the number of questions contained within an interrogatory and how many parties may be served to answer is governed by the Federal Rules of Civil Procedure. However, pursuant to civil law, local courts may further restrict the process. Generally, though, the number of questions per interrogatory is limited to 25 per party. In addition, since interrogatories are often used for the purpose of clarifying simple background information about the litigants, many lawyers prefer to use generic, pre-printed form interrogatories.
The use of the interrogatory is more common in civil procedures than in other types of actions, such as cases involving criminal law. For instance, it can be a valuable tool in a divorce lawsuit, where discovery of income and assets is necessary to determine equitable distribution between the parties. Interrogatories are also commonly used in personal injury lawsuits where negligence of the opposing party is alleged. Aside from providing background information, the interrogatory allows both parties to discover what facts and allegations will be presented at trial. However, there is one instance where an interrogatory may not be used--to take evidence from a witness.
Pre-trial discovery evidence to be gained from a witness is taken by deposition under oath. The witness, or deponent, is asked a series of questions by the opposing attorney directly and the entire process is recorded (and sometimes videotaped), as well as documented in a written transcript prepared by a court reporter. The opposing party and counsel are entitled to attend the deposition of any witness.
The deposition is a particularly useful device that may be used at trial to present first-hand witness testimony in the event that the witness becomes unavailable. For instance, if the witness in question were to become deceased prior to trial commencing, the transcript of his or her deposition may be provided to the jury in place of live testimony in the courtroom. In addition, it may be used to allege impeachment of the witness if live testimony contradicts admissions previously made during the deposition. Statements made during a deposition may also be used when a witness has difficulty recalling events relevant to the case.