The Project Lifesaver bracelets send out radio-tracking frequencies. Officers can follow the beeping signals using omni directional antennas.
Roseville Police recently had their first success story with the equipment. Spokeswoman Dee Dee Gunther says officers located a missing 13 year old autistic boy wearing one of the wristbands.
But she says police were puzzled when the trail ended at a concrete sound wall.
"..and then one of the officers got up and looked down and the child had concealed himself between the concrete wall and a bordering fence – a real small space. It’s very likely they never would have seen him without the equipment."
About a dozen Roseville residents are currently wearing bracelets. The free program is paid for with grant money from the Sutter Hospital Foundation and the City of Roseville.