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.

Presented by: Jane MacSorley and Tommy Ross KC

A Firecrest Films Production for BBC Sounds