During a recent mission, our SAR coordinator made use of the Reverse 9-1-1 system to contact homeowners in a particular subdivision in the area of the missing subject, to ask them to check around their homes and in their sheds and other out-buildings where the mentally handicapped boy may have been hiding.
Reverse 9-1-1 can be used to advise residents in both large and small areas of an emergency or hazard (ie. a hazardous material spill, a wildfire or flood, etc.), to gather information to help solve a crime, and, as in the case above, to alert them to a missing person search. The system might be used to assemble volunteers or to contact an individual for a welfare check. In addition, Reverse 9-1-1 can be used as a community bulletin board of sorts and even for automatic faxing of information or instructions to certain people or local businesses. It can also be used to reconnect to a phone that was disconnected during an emergency call.
The Reverse 9-1-1 system uses a database of phone numbers and addresses combined with mapping technology, allowing emergency and law enforcement personnel to pinpoint a specific area or individual/s. At this time, however, cell phone numbers and Voice Over Internet (VoIP) services such as Vonage or others offered by cable companies are not in the system. Some TTY (TeleTYpewriter) numbers may be in the Reverse 9-1-1 database, but emergency services don't know which phone numbers are TTY compatible. So if you don't have a land line but would like to be contacted on your cell, VoIP, or TTY phone, you have to register your number within your county or city. The system can deliver text messages to TTY and TDD devices, so those who are deaf or hard of hearing can receive the Reverse 9-1-1 alerts. You should also register if you have an unlisted phone number or have recently changed your phone number.
I would suggest doing an online search for Reverse 9-1-1 signup and the name of your area. Or you can call your city or county dispatcher. (But don't call 9-1-1 to do so, of course!) This is an example of Coconino County, Arizona's signup web page: Ready Coconino.
Here's a great example of how Reverse 9-1-1 can be effectively and successfully used in Search & Rescue operations: Reverse 9-1-1 System Used in Search for 77-Year-Old Woman