"If your mother's lost, the last thing you want to worry about is paying someone to find her," Tim Elfreth said.
Recent searches by the Keystone K-9s include Valley Forge Park in February for a missing Lower Providence woman and Levittown in December for a dementia patient who wandered away from home.
In the Levittown case, Petti Elfreth said, her bloodhound Clyde led authorities to a creek, where they found the woman's body.
Every Sunday morning and Thursday night - no matter the weather - the group trains, using people who volunteer to "get lost" so that they can be found by the dogs. On Sunday, the dogs practiced on Hatboro-Horsham High School's grounds using this reporter as their missing person.
Patti Elfreth said that "tracking dogs" follow a person's scent and path, and "air scenters" are trained to find any person anywhere. Of the three dogs participating Sunday, Clyde was a tracker; and Ace, an American black Lab, and Pip, a mutt, were scenters.
"Between the two types of dogs, you can find a person pretty fast," she said.
She wasn't kidding. Each dog found his well-hidden target within 10 minutes of hearing the magic word - "work" - although Ace thought that taking care of his personal business took priority over first finding this reporter. Pip also found this reporter, then promptly chased after squirrels.
"You're using the dog and working them, but it's also hide-and-seek," Patti Elfreth said. "They have no idea it's real when it is for real, so it's still a game to them."
Besides needing volunteers who can "get lost" for the Keystone K-9s, the group also seeks other dogs to try out to become part of the pack. The main requirement: Must love humans.
Debby Leo, Pip's owner and a retired detective from Cheltenham, said that volunteer dogs are an important supplement to trained police dogs because their demeanor is far more comforting to the lost and missing.
"Running down a burglar is a lot different than finding a little kid," she said.
For more information, visit the group's website, keystone-k9s-sar.cabanova.com.
Contact Stephanie Farr at firstname.lastname@example.org or 215-854-4225. Follow her on Twitter @FarFarrAway. Read her blog at PhillyConfidential.com.