Also known as: first-hand knowledge · first hand knowledge · personal knowledge
Written by attorneys · grounded in primary & secondary sources — see below
An evidentiary foundation requiring that a witness's or affiant's testimony or statement rest on direct sensory perception of the matter at issue rather than on hearsay or speculation. The foundation ensures reliability by demanding that the speaker perceived the facts through sight, hearing, or another sense. Courts apply the requirement at the threshold stage of admissibility before weighing credibility or accuracy.
Felicity French submitted an affidavit in support of summary judgment claiming that a delivery truck struck a pedestrian. She had reviewed security footage but never saw the collision herself. The court struck the affidavit because it failed to show that French possessed firsthand knowledge of the events described.
Frederick Ferguson testified at trial that he saw the defendant remove documents from a filing cabinet. Ferguson had entered the room briefly and observed the act through an open doorway. The court admitted the testimony after finding sufficient evidence that Ferguson had perceived the events directly.
Select any source to read its text and confirm it supports the definition.
Floyd Franklin presided over a contract dispute in which one party alleged that a key meeting never occurred. The judge had attended the same meeting years earlier in a different capacity. The judge recused himself because his personal knowledge of the disputed facts created an appearance of partiality.
Fabian Flynn told the jury during closing that he personally knew the defendant had never visited the accident scene. Flynn had not testified and offered no foundation for the assertion. The court sustained an objection because counsel may not assert personal knowledge of facts in issue unless testifying as a witness.
Faith Fitzgerald reported suspected attorney misconduct to the disciplinary board based on client statements rather than her own observations. The reported attorney sued Fitzgerald for defamation. The court dismissed the suit because the report enjoyed absolute privilege even though Fitzgerald lacked personal knowledge of the underlying facts.
Finn Fletcher offered a declarant's out-of-court statement identifying the decedent's biological father. The declarant had learned the information from relatives and never observed the relevant events. The court admitted the statement under the family-history exception because the rule expressly permits such declarations even without the declarant's personal knowledge.
A witness's own testimony describing the basis for the perception is usually enough. The proponent need only produce evidence from which a reasonable jury could find that the witness perceived the matter through one or more senses. Courts do not require certainty or direct corroboration at the foundation stage.
Supporting sources
No. The rule expressly exempts expert testimony offered under Rule 703. Experts may base opinions on facts or data not personally observed, provided those materials are of a type reasonably relied upon by experts in the field.
Supporting sources
The two doctrines are distinct. Even if a statement falls within a hearsay exception, the declarant must still have possessed firsthand knowledge of the facts asserted. The hearsay exceptions do not dispense with the perception requirement unless a specific provision, such as the family-history exception, creates an explicit carve-out.
Supporting sources
The objection arises under Rule 56(c)(2) when the material cited cannot be presented in admissible form. The opposing party should raise the objection in the summary-judgment briefing so the court can determine whether the affidavit satisfies the personal-knowledge mandate of Rule 56(c)(4).
Supporting sources
…Pp. 10–13. (b) An expert witness may voice an opinion based on facts concerning the events at issue even if the expert lacks first-hand knowledge of those facts. A long tradition in American courts permits an expert to testify in the form of a “hypothetical question,” where the expert assumes the truth of factual predicates and then…