Civil procedure: Federal Rules of Civil Procedure: Pre-trial procedure: Discovery (Part One)

Discovery, in the law of common law jurisdictions, is a pre-trial procedure in a lawsuit in which each party, through the law of civil procedure, can obtain evidence from the other party or parties by means of discovery devices such as interrogatories, requests for production of documents, requests for admissions and depositions. Discovery can be obtained from non-parties using subpoenas. When a discovery request is objected to, the requesting party may seek the assistance of the court by filing a motion to compel discovery.

History

Discovery evolved out of a unique feature of early equitable pleading procedure before the English Court of Chancery: among various requirements, a plaintiff's bill in equity was required to plead "positions". These were statements of evidence that the plaintiff assumed to exist in support of his pleading and which he believed lay within the knowledge of the defendant. They strongly resembled modern requests for admissions, in that the defendant was required to plead only whether they were true or false. At some point between the reign of Elizabeth I (1558-1603) and the late seventeenth century, positions were gradually replaced by interrogatories: written questions which the defendant was required to truthfully respond to under oath in his answer to the bill, based on information within his own personal knowledge as well as documents in his possession. But back then, interrogatories could only elicit admissible evidence (not the broader modern standard of "reasonably calculated to lead to the discovery of admissible evidence") and could only request evidence in support of the plaintiff's case, not either side's case (that is, they could not ask for evidence which the defendant intended to use in support of his defenses and was otherwise entirely irrelevant to the plaintiff's case). Even worse, this was purely a one-way procedure, because interrogatories could only be pleaded as part of a bill (a pleading initiating a suit in equity). A defendant who needed to obtain evidence in support of his defenses had to file a cross-bill against the plaintiff to plead his own interrogatories.

Discovery did not exist at common law, but its availability in equity attracted litigants in actions at law (legal proceedings in the common law courts). They began to file bills in equity to obtain discovery in aid of actions at law. This led to another innovation in the mid-15th century: the bill to perpetuate testimony of a potential witness. This was for witnesses whose advanced age or poor health implied they would not survive to testify at the trial of an action at law.

In this type of proceeding, the parties merely pleaded written interrogatories which were read out loud to the witness in a closed proceeding without parties or counsel present. The witness's attendance was secured by service of a subpoena ad testificandum at least 14 days before the date of the examination. In London, the examinations took place before a master or an examiner in Chancery Lane. Outside of London, the parties' attorneys were supposed to jointly stipulate to a group of lay commissioners (typically four, though only two were needed for a quorum) who could not be interested persons (for example, parties or their lawyers) and were usually country gentlemen. Once agreed upon, the court would grant them authority to examine witnesses by way of dedimus potestatem.