The first emergency alert system was created and implemented in Arlington, Texas, and named in memory of Amber Hagerman, a 9-year-old girl kidnapped and murdered in 1996. Since then, several states have created similar programs, known as Amber Alert systems.
A statewide program in California, titled Child Abduction Regional Emergency Alert, has been activated twice in the past month.
The California system helped police locate two teenagers Aug. 1 who were found within four hours of their disappearance.
An Amber Alert was issued Aug. 15 in Virginia, when a 9-year-old girl was kidnapped after her parents were found shot to death in the family's home. The girl has yet to be located.
Nevada's alert system was activated Tuesday when 10-year-old Nichole Timmons was abducted. The alert allowed Timmons to reunite with her family five hours after she was kidnapped.
North Carolina's alert system, titled North Carolina Child Alert Notification, is similar to what is in place in California. The system was configured by the N.C. Center for Missing Persons in 1998-99.
It was implemented in four counties in 2000 and has since expanded to 14 different counties -- including Orange and Wake.
John Goad, director of the N.C. Center for Missing Persons, said local law enforcement is charged with first response and will decide if an abduction case qualifies for NC CAN.
If the missing person is a child and is in danger of physical injury or death, the system will be used, he said. Runaways and parental abductions do not qualify.