The circumstances surrounding the murder of 23-year-old Rachel Nickell in July 1992, when she was attacked and killed in front of her two-year-old son Alex on Wimbledon Common. Colin Stagg was originally charged with the murder, but was eventually acquitted in September 1994 before the case went cold. With more advanced and refined forensic techniques available, Scotland Yard later reopened the investigation and in December 2008 Robert Napper - already serving time in prison for another killing - pleaded guilty to Nickell's manslaughter.