"One saved is awesome and we're hoping in the future we get many more out of this," Philadelphia Police Lt. John Walker said.
For years, police have been able to locate a stolen car using a device called LoJack.
Now, the makers of LoJack have created SafetyNet.
The subscriber to the service wears a bracelet which resembles a wristwatch that is constantly transmitting a radio signal.
Should that person go missing, Philadelphia police detectives use radio receivers to zero in on the person's signal and track the subscriber down.
"When he starts hearing this chirp, the detective knows he's within the area, within the range of a person that's missing," Terry Kelly of LoJack said.
That's how they were able to track a 72-year-old woman this morning who wandered off in the cold wearing only her nightgown. Police tracked her sitting in an unlocked car she stumbled upon at 67th Street and Haverford Avenue just eight blocks from her home.
"She was very thankful to the detective, thanked him multiple times and just basically said she was tired of being home," Walker said.
Subscribers to the service pay a $99 start up fee and then $30 a month afterwards. The service is available in Philadelphia and Lower Merion.
"We will soon be operational in Tredyffrin, Cheltenham and Bensalem and we're hoping by April, these areas will be operational," Tracia Tsakiris of SafetyNet said.
It was Councilman Jack Kelly who pitched the program to Philadelphia Police Commissioner Charles Ramsey a year and a half ago. During that time, 350 people in the department were trained on how to use it.
"Technology like this that can get us to a person a lot quicker, I think is a breakthrough and it's something the commissioner has supported," Walker said.
The program is available to anyone who suffers a cognitive disorder or brain trauma.
If you are interested in learning more, visit the official website of SafetyNet.