My brother is slowly killing our mother.

My brother has his own company. He's had it for past few years. It's a small company, but it's been fairly successful. About 2 years ago, my mother and I moved states. My brother was willing to take us both to work within his company. This, naturally, came with its share of problems: us being both employees and related to him, but both of us understood that we weren't warranted to any special treatment because of it. We were just like any other employee.

My brother, however, isn't that great with people. He, according to my mother, mistreated her as an employee, making all the affronts aimed at her seem very personal, even though one of his defenses was "that he treats everyone the same way" which however was not the case. He would make fun of her infront of the others, say something inapproriate about her or otherwise make her feel unwanted or hurt. She often made this clear to him and, despite some difficulties, he apologised, although it always took a while.
About 4-5 months ago, there was yet another incident between him and our mother. I'm not even certain how this all started, but so far my brother has failed to apologize and refuses to do so, which is apparent in him keeping her from coming to work at all. In September, she was send home for indefinite amount of time, for we were facing a season in which we were lacking with work and thus were unable to offer work to everyone, including my mother. My brother's motives however, were not made clear until very recently. My mother has now been unemployed ever since september, living completely off the goverment, which is bare minimum, even though right now we're facing more work than we have employess for. But my brother refuses to let my mother back, determined to drive her off to the street and also being uncooperative in assisting our mother to receive support from a union she's part off, while she is unemployed. She requires my brother to write a statement required for her to receive support from the union. but he either refuses to write it or sends an ineligible one.

My mother intends to contact a work safety official. If things continue like this, she is going to file a court issue and sue him, if that's what it takes. But I still feel like my brother holds all the cards here.
I feel helpless. I feel like I should be able to do something. I already help my mother financially, but my own salary just isn't enough to take care of both myself and her. The hatred I carry towards him is inmessurable. Whenever I see his face, I feel like choking the life out of him, but I know violence won't solve anything. But knowhing what he does to my mother... Doing nothing and I might aswell be doing this myself. Words aren't going to cut it either, I feel.

I require insight from someone outside of this situation. I wrote this now, even though I should be asleep already. Off to work once more tomorrow, But I had to write this, while my thoughts were on the subject. I feel like adding some more, more information, but I need sleep. Hopefully this piece of text offer some idea of the situation I'm facing and I will strive to answer any questions that may arise.
But I'm also not too hopeful for responses or help. And it's fine. I can't expect such.