Difference between "not remembering having said" and "never having said"?

Question

In the context of testifying about a claim made, what is the difference between these two constructs.

• "I never said that"
• "I don't remember saying that"

You're being asked to recall something.

Answer 1

"I don't remember saying that" is true unless you do remember and you did say that. "I never said that" is false if you said that. The former is a safer statement w.r.t. perjury (in case you actually did say that), because the prosecution would then have to prove that you did remember saying that (not impossible, but it is much more difficult to prove). Of course, the prosecution would have to prove that you did say that, to make a perjury charge stick.

Answer 2

"I never said that" is not perjury if the witness believes the statement to be true because, as noted elsewhere, knowledge that the statement is false is a necessary element of perjury. However, many people will recognize that memory is sometimes faulty, so they will say "I don't remember saying that" because they want to be careful about the assertions they're making. This can even happen when perjury is off the table, for example in an discussion between friends or family members:

Alice: I thought you said the library was closed.

Bob: I certainly don't remember saying that.

Lawyers may encourage this approach because even though it is difficult to prove that someone knew that "I never said it" was false, it is much easier to prove than it is to prove the same of "I don't remember saying it." After all, it's impossible for anyone other than the witness to know the witness's state of mind when they were on the stand with absolute certainty; as a result, we have various standards of proof in various contexts, and it's better to avoid having to deal with that if you can.

In other words, a prosecutor is less likely to pursue perjury charges for a "don't remember" statement, and it's to your benefit to reduce the possibility of being prosecuted even if you sincerely believe that you never uttered the statement in question.

(Of course, "I don't recall saying" might make a witness seem less credible or less reliable than "I never said," so the witness might want to take that into account, too.)