Hayley Cullen

So this is going back to the 1970s.

Cheryl Grimmer was a young girl who disappeared from Fairy Meadow Beach in Wollongong just on an ordinary summer's day.

And still to this day, Cheryl hasn't been found some 50 years later.

This case was a bit of a cold case for many years, but in recent years, the BBC actually put out a podcast about Cheryl's disappearance.

And on the back of hearing that podcast, there are a number of people who have since come forward who are at the beach that day or believe they have useful information that might actually contribute to reopening the case and legal proceedings.

What the concern is here is that particularly for one of these witnesses, they said that they remember being at the beach that day.

They saw Cheryl with a young man, but they didn't really think anything of it because she was just screaming like children do, right?

You know, even with parents, they scream sometimes.

And so it wasn't until hearing the BBC podcast that they really started to think that maybe they actually have really important information they need to provide to authorities.

What this basically means, though, is that they didn't interpret this event as a crime initially.

And 50 years later, they're starting to re-evaluate what they saw.

memory decays quite rapidly.

And so whether we can actually rely on the statement that someone's giving 50 years after an event when they've reinterpreted the experience is something that there's actually not really a lot of research about how that might impact the quality of the evidence that they give.

Ambiguous crime is a term that when I was first starting out as a researcher in eyewitness memory, I was looking into this.

I kind of had to create it as a term.

But what I meant in saying it's ambiguous is that some kidnappings, you know, we have what we call schemers, which are event representations, like how we typically expect an event is going to unfold, right?

Now, when you go to the movies, you kind of know you're going to go get your popcorn.

You sit down.

There are previews.

The movie starts.