Sociopaths are unable to sympathize empathize put themselves in someone else's shoes. Missing that DNA? Know any?

I suspect my half-brother might be a sociopath because when I think about it up I can't think of a time when he ever displayed any kind of concern or empathy for other people whatsoever.  He was a lot older than me so I was never in school with him but I do know he was a bully in school.  He just got away with it because he always knew how to suck up to the right people like the teachers and the principal.  

He's a career criminal now.  He just started his second prison sentence for burglarizing self-storage units.  He was only out of prison for I think two months when he was caught again.  His first prison term was also for self-storage unit burglary so yeah, just not a high-end criminal like jewel thieves.  It didn't help his case that he was caught transporting his plunder in a stolen pick-up truck but he swears his friend let him borrow it and he didn't know his friend stole it.

He was already criminally career-oriented in high school.  He went to a boarding school in another state where he was caught shoplifting from the local Wal-Mart but my parents really tried to stay hush-hush about that.  It's one of those things I wasn't supposed to know.