If video filmed by (say) a smartphone is used as evidence, does the person who filmed it have to submit an affidavit saying "I filmed that at location X at time Y"? Or can the video be used as evidence without that?

3 Answers 3


If video filmed by (say) a smartphone is used as evidence, does the person who filmed it have to submit an affidavit saying "I filmed that at location X at time Y"? Or can the video be used as evidence without that?

Short Answer

Someone must testify to authenticate video evidence but it doesn't necessarily have to be the person who filmed it and an affidavit would frequently not be sufficient to do so.

Long Answer

There are two main kinds of evidence: exhibits and testimony. Videos are a form of exhibit even though they may sometimes record testimony (and videos of depositions and trial testimony are often treated as testimony rather than exhibits for many purposes).

Video evidence (like all other exhibits) must be authenticated to be admitted in court and considered to resolve disputes presented to a court (at least in common law court systems like England, the U.S., Australia, etc.)

Authentication means to provide context to show what the evidence is and how it came to be and that it is what it purports to be. Some of the evidence provided to authenticate an exhibit is also called "foundation."

The burden of proof to authenticate a document is a fairly low bar. Generally, if a party can provide prima facie evidence sufficient if believed to be true to authenticate an exhibit and another party disputes its authenticity, the exhibit is admitted and the question of authenticity at that point becomes one for a judge or jury as a finder of fact to weigh based upon all of the evidence, and not a question regarding whether or not the evidence can be admitted for consideration at trial.

There are multiple ways that evidence can be authenticated, and this is not limited to testimony from the person who took the video. Someone who was present when the video was taken, for example, could also authenticate it. A chain of custody is often part of proof of authentication. Any way to prove that the evidence is what it purports to be and to establish what it purports to be that logic and reason supports is allowed.

There are a few kinds of exhibits that are self-authenticating (e.g. government documents under seal), but video evidence rarely qualifies as self-authenticating (in part because it can be manipulated and someone needs to testify that it was not manipulated).

There are other kinds of evidence which may be authenticated by affidavit under safe harbor provisions of rules of evidence, such as certain evidence provided in response to a subpoena duces tecum (i.e. a subpoena to produce documents) in some jurisdictions.

But the general rule is that an affidavit is not sufficient and that exhibits including video evidence must be authenticated with the live testimony of a witness under oath who has personal knowledge of the facts to be established which is subject to cross-examination.



People say things like “video evidence” but that video is technically an exhibit. The evidence is the testimony by a person about what the video is.

  • 1
    I would consider exhibits to be a subset of the things that are evidence, with testimony being the other main subcategory of evidence. Both the video, once admitted as an exhibit, and the testimony about what the video is would be evidence, although different kinds of evidence.
    – ohwilleke
    Commented Nov 11, 2020 at 23:56

It'd certainly help.

Having the filmer available allows them to provide necessary context. This includes attesting that the video has not been edited, that it is in fact of the relevant location and time, and explaining any inconsistencies in it. They can also be cross-examined over this.

Without a witness to cross-examine, it is possible the video would be dismissed as hearsay.

  • The video might not be admitted as evidence, but hearsay would be the objection raised, for example, to the authentication affidavit and not to the video itself. The video itself would not be hearsay although it might contain objectionable hearsay statements that would have to be suppressed under the hearsay rule in some cases. The objection would be lack of foundation or lack of authentication.
    – ohwilleke
    Commented Nov 11, 2020 at 23:53

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