October 2 marked the beginning of a 23-day shooting spree that wrought terror on the US capital during the Autumn of 2002. An anonymous sniper randomly targeted unsuspecting area residents without regard to age, race or gender. Washington DC was paralysed by the threat of an invisible killer who could strike anywhere, at any time. Montgomery County, Maryland police Chief Charles Moose (Charles S. Dutton) arrives at work that October morning to hear the news of a shooting in a nearby Washington, D.C. suburb. A landscaper, mowing a lawn, was shot at long range with a high-powered weapon. The details are eerily similar to a homicide he investigated the evening before in which a shopper leaving a grocery store was gunned down in the same manner. As chief Moose begins to put the pieces together, the news comes in - another victim. This time it's a taxi driver struck down by a single bullet while refuelling at a petrol station. Chief Moose's worst fears are confirmed. A serial killer is on the loose and it's only a matter of time before he strikes again. Local media urges local residents to stay alert and not to panic at a time when a trip to the supermarket, garage or playground could be deadly.