If it's his cat, I have no clue how he and his family lost him. Unless he was an outdoor cat. We had an outdoor cat long ago named Alli, who we lost while we were on vacation. A kind man heard we lost her and brought her back thankfully, she was stunning, all white (and she was pregnant when we got her- gave away the kittens and kept her). And we haven't had an outdoor cat since then, maybe 15 years back.

He asked if it was the animal shelter speaking when I answered, so I think he was trying to contact them.

We have no clue if he's a purebred. The vet guessed domestic shorthair. He was quite young when we first saw him, and came to our house for maybe a few months on and off.

I wouldn't keep him from him if he is their cat, but I would need absolute proof. Luigi didn't ACT feral when he used to come to our door, and looked like he had belonged to someone initially. We just assumed he was a stray or an outdoor cat that a neighbor owned, until he got into a fight (probably how he got the FIV).

In the end, the microchip is the deciding factor. No chip, no ownership. I will keep you posted. My mom will be home shortly, and then we'll have to discuss the next step.