As the trial draws towards a conclusion, the jury are introduced to a science lesson. Can microscopic algae, found in the River Leven, help answer the question of whether any of the accused entered the water? The jury also hears from some police officers involved in the original enquiry, finding out why the accused weren't brought before a court at the time. And as the final witness completes their testimony, the jury are sent away, ahead of the closing speeches, and the opportunity to reach a verdict.

Presented by: Jane MacSorley and Tommy Ross KC Written and Produced by: Darrell Brown Production Manager: Eilidh Hart Executive Producer: Iain Scollay Commissioning Editor: Heather Kane-Darling

A Firecrest Films Production for BBC Sounds

After seven days of evidence for the prosecution, it's time for the defence to lead the evidence. And they start with testimony from one of the three accused. Can their account convince the jury of their innocence? Or will the cross-examination prove to be damning? Also taking the stand are two witnesses who support the idea that George Graham may be culpable. What value will the jury put on these claims?

Presented by: Jane MacSorley and Tommy Ross KC Written and Produced by: Darrell Brown Production Manager: Eilidh Hart Executive Producer: Iain Scollay Commissioning Editor: Heather Kane-Darling

A Firecrest Films Production for BBC Sounds

What did the three accused say when they were quizzed by detectives? As the prosecution case comes to a close, we hear extracts form those interviews. We learn how all three insist they had nothing to do with Caroline's death. And hear the observations of the officers tasked with obtaining their account. Then - in a dramatic twist - the prosecution announce that one of the charges in the case is set to be dropped. What does this mean for the rest of the trial?

Presented by: Jane MacSorley and Tommy Ross KC Written and Produced by: Darrell Brown Production Manager: Eilidh Hart Executive Producer: Iain Scollay Commissioning Editor: Heather Kane-Darling

A Firecrest Films Production for BBC Sounds