The drama continues, though I wish it wouldn't

I've got some questions, so please bear with me.
I received a call today from the woman with whom my younger brother is staying. She's the mother of his friend. Her message began with thinly veiled contempt, escalating to obvious rage and hate throughout the conversation. Her overall point was thus: family should not let family go homeless.
Her points were reasonable, and I could see where she was coming from. People need second, third, etc. chances, but this, IMO, is for people who
wish to change. Her understanding of what transpired here was more or less accurate, but her intense anger really makes me think she's been "handled," so-to-speak.
I'm starting to believe that my younger brother is a sociopath. He fits
most of the qualities as listed here:
Profile of the Sociopath. I've never,
ever seen him feel guilty for his actions, not in all the 19 years I've known him. If ever I've seen him upset, it was because of something that happened to him, not because of something
he did. And it usually had a purpose, often ending with him getting his way. I could list in detail things I've seen him do, and how they match up to the criteria, but I won't put you through it.
It should also be mentioned that I can never truly feel comfortable around him. I'm always uneasy when he's around, like he's about to do something shady. Granted, I'm phobic of people in general, but I always get a vibe from them, which gives me an idea of whether or not they are harmless. My internal buzzer goes off nonstop when my younger brother is near, and it's due to that "off" feeling mixed with my knowledge of his history.
Am I being too judgmental of his actions? Do you think I'm grossly misinterpreting his intentions? Can I, having known him all his life, determine whether or not he is in fact a sociopath?
Should I try again and give him another chance? And another, and another? (even though I seek your opinion on this matter, I will
not take him back, but I would like your input if you share from that woman's point of view)
I know he's family and all, but I don't like being played, or having him
think he's playing me
