Definition
Perpetuating testimony is a procedural mechanism for formally capturing and preserving the testimony of a witness before the litigation in which that testimony is needed has been filed or reached the stage of ordinary discovery. The core concern is loss: the witness may die, become incapacitated, or leave the jurisdiction before a lawsuit is commenced or before trial. By perpetuating the testimony, a party creates a durable record that can substitute for the live witness when the moment of need arrives.
Under modern practice, perpetuating testimony before an action is filed is governed by Federal Rule of Civil Procedure 27 in federal court, and by analogous state rules. After an action is pending, the same need is largely addressed through the standard deposition rules.
Common Confusion
PERPETUATING TESTIMONY vs. ORDINARY DEPOSITION: The two procedures are closely related in mechanics — both typically involve sworn examination before an officer — but differ in timing and purpose. An ordinary deposition is taken during pending litigation to gather information and lock in testimony for use at trial. Perpetuating testimony is invoked specifically when litigation has not yet begun, or when a trial is indefinitely delayed, and the risk of losing the testimony altogether justifies extraordinary pre-suit judicial action. The standard is higher: the petitioner must ordinarily show that the prospective testimony may be lost and that the subject matter is cognizable in a court. A deposition taken in pending litigation carries no such threshold burden.
PERPETUATING TESTIMONY vs. PRESERVATION DEPOSITION: Some practitioners use "preservation deposition" colloquially to describe any deposition taken primarily for trial use rather than discovery. This usage overlaps but is not identical with the technical procedural device of perpetuating testimony under Rule 27 or its equity predecessors.
Core Elements
To obtain leave to perpetuate testimony under the modern federal framework, the petitioner must generally establish:
1. ANTICIPATED LITIGATION: The petitioner expects to be a party to an action cognizable in federal court but cannot currently bring or cause it to be brought.
2. SUBJECT MATTER OF THE TESTIMONY: The petition must identify the subject matter of the expected action and the testimony sought.
3. IDENTITY OF WITNESSES: The petitioner must name the expected adverse parties and the witnesses whose testimony is to be taken.
4. RISK OF LOSS: The petitioner must demonstrate that the testimony may otherwise be lost — through death, illness, advancing age, or prospective departure from the jurisdiction.
5. NOTICE: Prospective adverse parties must receive notice and an opportunity to participate.
Why It Matters in Research
Researchers will encounter perpetuating testimony across two distinct legal worlds that must not be conflated: the equity tradition and the modern procedural rule.
In historical sources and older case law, perpetuating testimony was primarily an equity procedure. A party filed a bill in equity — a "bill to perpetuate testimony" — and the court of chancery exercised discretionary jurisdiction to take the testimony before any common law action was ripe. This is what Blackstone describes and what all three dictionary sources here reflect. Researchers working with pre-twentieth-century materials should expect the procedural home to be equity reports and chancery practice manuals, not common law reporters.
The modern federal rule (FRCP 27) codified and rationalized this procedure, but abolished the equity/law divide that shaped the older doctrine. State courts vary: some track Rule 27 closely, others preserve older equity-influenced standards or have statutory regimes. A researcher tracing a doctrine from equity precedent through modern practice must account for this transition.
There is also a recurring trap in older sources: the phrase "perpetuating testimony" was sometimes used loosely to describe any deposition taken with an eye toward preservation, not only the formal pre-suit equity proceeding. Context — particularly whether litigation was pending — is the key to accurate reading.
Finally, the remedy is narrower than it may appear. Courts have consistently held that perpetuation under Rule 27 is not a substitute for discovery, nor a fishing expedition to identify whether a claim exists. The petitioner must already know what testimony is needed and why it is at risk. Researchers looking for cases where Rule 27 petitions were denied will find a substantial body of authority emphasizing this limitation.
Historical Dictionary Support
Black's (both editions) and Burrill agree on the essentials: this is a proceeding to take and preserve testimony before trial, available when testimony is in danger of being lost. All three sources cite Blackstone's Commentaries (3 Bl. Comm. 450) as the foundational authority, placing the doctrine firmly in the equity tradition.
Burrill adds useful procedural texture that Black's omits: the procedure was accomplished "by bill filed in equity for that purpose, and sometimes by proceedings at law," and Burrill's references to Story's Equity Jurisprudence (§ 1505 et seq.) and Story's Equity Pleading (§ 600 et seq.) point researchers toward the richest classical treatment of the subject. The phrase "before the matter to which it relates can be made the subject of judicial investigation" in Burrill is particularly precise — it captures the pre-suit, anticipatory character of the remedy more clearly than Black's language about testimony lost "before the trial."
What the historical dictionaries do not address: the modern procedural transformation under FRCP 27, the abolition of the equity/law procedural distinction, or the ongoing judicial debate about whether Rule 27 permits use of perpetuation procedures to identify potential claims rather than preserve known testimony. For those questions, researchers must move beyond the shelf dictionaries to treatises and case law.
Jurisdictional Note
Federal practice is governed by FRCP 27. Most states have analogous rules, but some retain equity-influenced standards that impose stricter requirements on the petitioner or require a showing the federal rule does not explicitly demand. State appellate courts in jurisdictions that preserved separate equity courts longer than most may have a richer body of perpetuation-of-testimony precedent than the federal courts.