The broadcast will be repeated every 15 minutes for the first four hours, then at the start of each hour for the next eight hours. It also will include a phone number for the public to call. Spotsylvania authorities are coordinating the effort, which they say could be expanded to include other nearby jurisdictions. Authorities yesterday cited national crime statistics showing that most children who are abducted and murdered typically are killed within three hours of their kidnapping. Silva's body was found five weeks after she disappeared from her front porch on the afternoon of Sept. 9, 1996.
Investigators believe the same killer is responsible for the crimes, which remain unsolved.
Authorities have not said how the girls died, although sources have confirmed the Lisk sisters were asphyxiated. Authorities said they do not plan to use the new alert system for situations involving runaways or in most child-custody disputes because its effectiveness could be diluted if listeners tune out broadcasts over time. Spotsylvania authorities estimate they might have activated the system two or three times in the past year had it been in place. By comparison, the sheriff's office receives 20 to 25 reports of runaways per month. Authorities said they usually can discern within an hour whether foul play is involved in a child's disappearance.