Vet him as if he was going to be your President. Check his story, all of it. Find out if he has friends. If he was living with mom then he should have plenty of friends in his neighborhood to vouch for him.
I have many years of working with the homeless. Do NOT let them into your home, especially if you have a family. Do NOT give them money unless it is done in a dispassionate obedience in the spirit, not from being swayed by a sob-story heart-tug.
There is so much money and help and food and shelter available to aid the truly needy 100 times over. That he will not avail himself of it is a big ol’ red flag.
Many thanks! I will ask Mitt to lay out his case but trying to do it in a dignifying manner.