Three boys from the same Sunderland school were found dead within a few months of each other in the early 1990s. Their deaths were initially blamed on sniffing glue to get high. But the boys' families thought they had been murdered. And they were right. Two years later, Steven Grieveson was convicted of serial murder. But the investigation wasn't over.

Presenters: Criminal psychologist Dr Julia Shaw and journalist and true crime documentary maker Amber Haque.

Producers: Maggie Latham and Rachel Oakes