The Alert System broadcasts three different alerts; AMBER, Blue and Silver.
Amber Alerts - The Arizona AMBER Alert Plan is a voluntary partnership between law enforcement agencies and broadcasters to send out an emergency alert to the public when a child is abducted.
Blue Alerts - A Blue Alert is activated when a suspect is at large about killing or injuring a law enforcement official and pose a threat to the public or law enforcement community.
Silver Alerts - A Silver Alert is activated when an adult over 65-years-old is missing.
There are 108 ADOT message boards across the Valley and 193 statewide.
An alert's location will determine how many signs flash the information, because law requires that officials spread the alerts only in the region where the crime or disappearance took place.
The new alerts were signed into Arizona law in 2014. Federal law doesn't allow the use of infrastructure the same way for Blue and Silver alerts as Amber alerts, but AZDPS can use these signs because they're state owned.
The Silver Alert for Frederick Snow has been cancelled. Today at 2018 hours, Frederick was located and is at his residence. He was safely recovered. See Arizona DPS website for further information and photo: http://www.azdps.gov/Media/Alert/.
Today 11/13/18 at 1030 hours Mr. William Watson was recovered by an AZ DPS Trooper at EB US 60 and Gilbert as a result of the Silver Alert. Mr. Watson is in good condition and the Silver Alert is cancelled.
Police seek public assistance to locate missing elderly man