Project Lifesaver

The Project Lifesaver Program is a rapid response system that helps the Atlantic County Sheriff's Office track adults and children who tend to stray due to Alzeimer's Disease, autism, Down Syndrome or other conditions.
Each client is given a bracelet that transmits an individualized tracking signal that can be picked up within a one mile radius.  Most who wander are safely found within a few miles from home.

http://www.nbc40.net/story/23464006/atlantic-co-sheriffs-dept-find-missing-person-using-project-lifesaver
To learn more about this program, see link below:
http://www.acsheriff.org/main/programs/lifesaver.asp