Definition
To discredit, in legal usage, means to undermine or destroy the credibility of a witness, document, or other evidence. The goal is to reduce or eliminate the weight a factfinder would otherwise give to that witness's testimony or that piece of evidence.
Applied to witnesses, discrediting is accomplished through several recognized methods: attacking the witness's general character for truthfulness, exposing prior inconsistent statements, demonstrating bias or motive to lie, or establishing facts that call the witness's perception or memory into question. Applied to documentary evidence, discrediting typically means challenging the document's authenticity, accuracy, or chain of custody.
Discrediting a witness is the broader category of which impeachment is a subset — though the two terms are used interchangeably in most practice contexts.
Common Language
Modern common usage (Wiktionary): To harm the good reputation of a person, or to cause an idea or piece of evidence to seem false or unreliable.
Historical common usage (Webster's 1913): The act of disbelieving or the state of being disbelieved; some degree of dishonor or ill repute; reproach applied to persons or things.
The common meaning is reputational and social — to discredit someone in ordinary speech is to damage how others think of them generally. The legal meaning is narrower and procedural: discrediting occurs within the context of evidence and trial, and its purpose is not to harm a person's reputation at large but to reduce the evidentiary weight of specific testimony or documents before a specific factfinder. A witness can be legally discredited at trial without any lasting social consequence, and vice versa.
Common Confusion
Discredit and impeach are frequently used interchangeably, and for most purposes the distinction is unimportant. However, impeachment is the more technically precise term in evidence law, often referring specifically to the formal process of challenging a witness's credibility through recognized procedural mechanisms — including prior inconsistent statements, convictions, bias, and reputation for untruthfulness. Discredit is the broader concept: all impeachment discredits, but some discrediting (such as undermining the foundation of documentary evidence) does not fit neatly under the heading of impeachment as traditionally framed. Researchers encountering either term in historical sources should treat them as functionally equivalent unless the source draws an explicit distinction.
Recognized Forms
/SUBTYPES
Historical sources, particularly Rapalje & Lawrence, enumerate the principal methods by which a witness may be discredited:
1. Character evidence: Introducing evidence of the witness's general bad character for veracity, or cross-examining on that subject.
2. Prior inconsistent statements: Showing that the witness has on prior occasions made statements inconsistent with current testimony relevant to the matter in issue.
3. Misconduct: Proving specific acts of misconduct bearing on truthfulness, subject to rules limiting extrinsic evidence on collateral matters.
4. Bias or interest: Establishing that the witness has a personal stake in the outcome or a relationship with a party that compromises objectivity.
5. Attacking documentary evidence: Challenging the genuineness, authenticity, or accuracy of a document rather than the testimonial credibility of a person.
Why It Matters in Research
Researchers working in trial practice materials, evidence law, or procedural history will encounter discredit throughout as a working term. Several navigational points deserve attention.
First, the term's scope has narrowed and formalized over time. Older sources use discredit broadly to describe any erosion of a witness's standing — including reputational character evidence that modern evidence rules now sharply restrict. Federal Rule of Evidence 608, for example, limits character-based discrediting to reputation or opinion testimony about truthfulness and bars most specific-instance evidence except on cross-examination. Pre-FRE historical materials will reflect a more permissive landscape.
Second, the question of who may discredit whom has evolved significantly. Bouvier flags the classical rule that a party could not impeach its own witness — the voucher rule — meaning you were bound by testimony from witnesses you called. Modern rules (see FRE 607) have abandoned this restriction entirely. Any historical source invoking the party-calling limitation should be read in that context.
Third, discrediting documentary evidence is treated differently across source types. The evidentiary dictionaries focus almost exclusively on witness credibility; document-focused discrediting (attacking authenticity, chain of custody, or accuracy) is addressed more thoroughly in evidence treatises than in the historical legal dictionaries.
Fourth, the corpus distinction between discredit and impeach rewards attention: older English-origin sources (Burrill, Bouvier) favor discredit as the governing term; later American practice materials increasingly standardize on impeach. Both map to the same underlying concept.
Historical Dictionary Support
The historical dictionaries are consistent in their core definition and differ mainly in scope and emphasis.
Black's (both editions) defines the term most broadly, including attack on documentary evidence alongside witness credibility, and explicitly covers "any means whatever" — signaling that the methods are not exhaustive. This breadth is useful when researching practice before modern evidence codes formalized specific categories of impeachment.
Burrill focuses tightly on the witness context and frames discrediting as rendering credibility "doubtful" — a useful reminder that discrediting does not require complete destruction of a witness's credibility, only meaningful diminishment.
Bouvier adds the procedural dimension most explicitly, noting the classical rule against impeaching one's own witness and explaining that discrediting the opposing party's witness was standard practice. This is the entry most useful for understanding the adversarial framing of the term in nineteenth-century practice.
Rapalje & Lawrence provides the most structured analytical breakdown, enumerating specific methods — character evidence, prior inconsistent statements, misconduct — in a way that anticipates modern categorical treatment in evidence codes. Researchers tracing the intellectual lineage of FRE 608 and 609 will find Rapalje a useful precursor.
Anderson simply cross-references CREDIT, which is typical of entries that presuppose background knowledge. That cross-reference is nonetheless useful: researchers should consult credit entries in period dictionaries to understand the underlying concept being attacked.
None of the historical sources engage with the discrediting of electronic or digital evidence — an absence that reflects the period and should not be read as a doctrinal limitation. Modern treatment of that issue lies entirely outside this corpus.
Jurisdictional Note
The mechanics of discrediting vary by jurisdiction primarily in the rules governing character evidence, prior conviction evidence, and the permissible scope of cross-examination. Federal practice is governed by FRE 607–609; state codes largely parallel but sometimes diverge on admissibility of prior convictions and the scope of collateral matter rules. Researchers working in specific state courts should consult the applicable evidence code rather than extrapolating from federal doctrine.