Kate, who was head girl at Gumley Convent School in Isleworth, had earlier given a speech at her school-leaving service and was returning from a night out celebrating-with friends when she was hit by the car on Saturday. One theory is that she was deliberately targeted. Detective Sergeant Phillip Ryan said: "This was a callous act. We are exploring all avenues but cannot understand why she should have been targeted. She does not appear to have any enemies."