Information about Nancy Guthrie's pacemaker helped authorities piece together a new timeline in her kidnapping. Can the devices track you?

Authorities believe Nancy Guthrie, 84, was taken from her home, outside Tucson, Arizona, "against her will," and they are now offering a $50,000 reward for information that leads to finding her.

The FBI and Pima County Sheriff’s Department this afternoon said it is aware of a “new message regarding Nancy Guthrie.