Discovery Definition

A formal investigation—governed by court rules—conducted before trial by all parties to a lawsuit. Each party does discovery to find evidence it can use to present claims or defenses at trial, to find out what evidence other parties will use at trial, and to support its position during settlement negotiations.

The most common types of discovery are:

  • interrogatories—written questions the other party must answer in writing and under oath
  • depositions—one party to a lawsuit asks questions of another party or their witnesses under oath while a written transcript is made by a court reporter
  • requests to produce documents or things—one party can compel another party to produce documents or other tangible evidence, and
  • requests for admissions—one party asks another party to admit or deny key facts in the case.

Discovery also happens in criminal cases. The prosecutor must turn over to the defense all witness statements and other evidence that might tend to prove the defendant's innocence. Depending on the court rules, the defendant might also be obliged to share evidence with the prosecutor.