Besides saving dogs possibly doomed to die, the charity will help police departments: Dogs professionally trained as police K-9s from puppyhood can cost $8,000 or more, according to the National Police Dog Foundation. The Throw Away Dogs Project, which already donated one rescued dog to the Maryland State Police, gives dogs to departments for free.
Walters said he and co-founder Carol Skaziak came up with the idea last December.
Skaziak does public-relations work for Philadelphia Pet Hotel and Villas, where Walters boards Winchester and his family dog, Trigger, during vacations.
"At least once a month, dogs were being left at the hotel," Skaziak said.
Skaziak was so outraged that she featured rescued dogs in a 2014 calendar, with Winchester as the cover dog. Proceeds paid for a year's worth of dog food for New Leash on Life USA, a charity that rescues abandoned dogs. Skaziak is now recruiting dogs for a 2015 calendar.
Skaziak and Walters partnered to create the Throw Away Dogs Project because they wanted to move beyond fundraising to saving lives, Walters said.
And the bosses appreciate that the effort could save money, too.
"We're always looking for ways to streamline the cost of our operations," SEPTA Police Chief Thomas Nestel said.
The enterprise is not foolproof: Shelter dogs don't always work out as police dogs. K-9s professionally trained since they were puppies are expensive partly because their performance is guaranteed, Walters said.
Still, Walters said, none of the K-9s he knows that have been plucked from shelters (SEPTA has two and Philadelphia police have five) has failed in their duties.
Winchester is an explosives-detection dog also trained to patrol and apprehend. In his three years on the SEPTA police force, he hasn't found any explosives nor had to apprehend anyone, Walters said.
"Unfortunately, the transit system is a prime target for terrorist activity. We haven't had any. But it is a concern we have to try to prevent," Nestel said. "Dogs are a tremendous way to clear unattended bags very quickly. Rather than stop the entire system every time a suspicious bag is found, we're able to deploy a dog in minutes and clear it."
The dog's mere presence - Walters and Winchester primarily patrol transit hubs like Center City - often defuses problems, Walters said.
Just glancing at him, it's easy to see why. He's a "heavy breather" who looks, even as he lays at Walters' feet, like he's itching to run a marathon - and win.
Yet, although he might intimidate some troublemakers, he appreciates a good belly rub and ball toss, and he doesn't mind when Walters' toddler plucks his hairs out one by one or uses him as a couch.
Best of all: He requires no pay or treats for his hard work.
"Give him his ball or his squeaker toy, and he's happy," Walters said.
On Twitter: @DanaDiFilippo