Questioning a witness years after an event...

I’ve always wondered, how useable would testomony of a witness be in a trial for a crime or event that happened years ago?

What type of details would they expect a witness to remember?

I can barely remember any significant details of events that have happened in the last month let alone 3-5 years ago!

I posted this after reading the police were questioning Leonardo Di Caprio about a brawl that happened 5 years ago. It was outside a club and I’m sure alcohol was involved. Do you really think Leo could remember any details from this event?


The testimony would be fully “useable” in the sense that it is admissible in court. But it would be subject to attack for the reason that you suggest: memory usually fades with time. The party offering the testimony would probably try buttressing it by showing, for example–[ul][li]that the witness can accurately recall other events from around the same time;[/li][li]that the witness can accurately recall other details concerning the same event–for example, if Mr. DiCaprio can correctly identify by name the manager and each employee on duty at the club on the night of the brawl, and his recollection matches the club’s records, then it is less of a stretch believing that he is correctly remembering other details; or[/li]that the event impressed the witness is some vivid way that makes it unforgettable–for example, I don’t remember much about how I spent the morning of 10 September 2001, but I very clearly recall how I spent the following morning.[/ul]The other party would try showing the opposite. There are other ways of refreshing a witness’s recollection, too, such as showing him or her a photograph of a dimly remembered event in order to identify the persons appearing at the scene.

“Goes to weight!”

That’s what trial lawyers say when confronted with this issue – the testimony is obviously less reliable or creditable 5 years later than it would have been three weeks after the incident, but it is up to the jury to decide how much mojo the witness has lost over that time, and to weigh that against whatever other testimony is offered in the matter – with whatever creditability problems that testimony may itself have. As brian notes, testimony can be supported or attacked for a variety of reasons.

At some point testimony is so weak that it should not be admitted at all in that its probative value is outweighed by the improper prejudice it will inflict, but exactly when a given piece of evidence passes that line is a fuzzy one, and you can expect that the lawyer offering it will say the problems go to weight while his opponent will claim it has so little probative value it must be excluded.


Old memories can also be contaminated by outside sources. In Case Closed Gerald Posner did a marvelous job of showing how comments on the Kennedy assassination changed markedly over time because witnesses were influenced by conspiracy theories into thinking they should have seen things that were nowhere in their original statements to the police.

In experiments about one-third of people can be made to think they saw Bugs Bunny at Disney Land just by showing them a phony brochure with Bugs on it. You’ll want to look into the research of Elizabeth Loftus. You can start with her homepage. She’s very well respected in the field of memory and has done a lot of ground breaking work on eye witness testimony.

And aren’t we supposed to believe the movie stars? After all, they’re famous.

The phenomena that Exapno Mapcase and js_africanus describe are not limited to a witness recalling an event in the remote past. Sometimes a witness’s recollection of a very recent event, especially an event that happened quickly and unexpectedly and with a confusing level of detail, can be influenced in the same ways–for example, when witnesses to the same scene compare notes with each other other, and each witness “absorbs” cues from the other witnesses’ versions into his or her own perception of the memory.

Just to clarify, I could care less about Leo. I just used him as an example.

I was mainly thinking about a trial that just started-up in Vancouver.

They are trying (sp?) 2 guys for the Air India bombing incident that happened in 1985. I can’t see any witness testimony being used for either side, this was 18 years ago!. I hope they have some physical evidence to get these guys.