Introduction:

In October 2002, the suburbs of the US capital Washington DC were gripped by a bizarre reign of terror. Randomly chosen residents going about their daily business were killed or injured by a sniper using a high velocity rifle.
John Allen Muhammad, 42, has been found guilty of murder, terrorism, conspiracy and firearms charges. His 18-year-old stepson John Lee Malvo (also known as Lee Boyd Malvo) is being tried. BBC News Online looks back at the serial killings that left 10 people dead and three injured.