What ever happened to Olivia's brother? We met him in season 8 but that was the last we heard about him?

We've only seen him in pokok episodes, all season 8 (Philadelphia, Florida and Screwed). In that last episode Olivia was in trouble with internal affairs for giving him money after he jumped bail. He tells her he lied to her captain to get her out of trouble sejak telling Cragen she didn't know that he'd jumped bail and that he threatened her to tell him about their relationship. After that he leaves, and so far we haven't seen him again. Hope it helps!

Simon showed back up in Season 13, seeking Olivia's help with his kids.