What effective response can the prosecution give to a witness who uses the term "I cannot remember ..."

[thedaveformula]

Surely since forgetting things is part of being human, (I forget my keys or bank card) how would a prosecution lawyer go about proving that the issue that the witness can't remember actually happened?

Assuming the witness was not under the affects of a chemical, the only way I can think to go at it is this. Put it to the witness that failing to remember what happens during a criminal act is very strange, and if he can't remember this specific incident then what else in his testimony is credible at all?

[bednobs]

i think the jury will draw their own conclusions

[sandyRoe]

The witness might have been shocked by what he had seen and really not remember. But selective amnesia would cast some doubt on the credibility of the rest of his evidence.

[karenmac60]

But surely the witness will have given statements before the case comes to court. If they had claimed in their original statement not to remember what happened would they be called as a witness? If they remembered at the time of giving their statement then it is unlikely that they have forgotten in the meantime.

[thedaveformula]

Good point if you're talking about criminal case, but a civil case would have no such original statements.

[dotty.]

there is a paper trail even in a civil case, but you used the term 'criminal act' and so you're probably meaning a criminal case anyway are you not?

[thedaveformula]

yes sorry