In February 1993, a two-year-old boy called James Bulger was murdered in Liverpool. CCTV pictures showed two 10-year-olds leading James from a shopping centre towards his brutal death on a railway embankment. Witness speaks to Superintendant Albert Kirby, the officer in charge of one of the most sensitive investigations in British police history.

PHOTO: Jon Venables and Robert Thompson, the killers of James Bulger. (Press Association)