Thank you for the information. If you have already spoken to HR or other attorneys in the office, then you might know that unless the harassment and bullying is motivated by discrimination against the target because they are a member of a protected class under employment discrimination laws, it is not legally actionable. In other words, "hostile work environment" harassment, which is the only actionable workplace harassment, is a legal term of art created by the Supreme Court in describing a type of unlawful discrimination.
So, since you say this person is not motivated by discrimination and treats many, if not most, people this way, then there would be no cause of action. Even if he was motivated by discrimination the cause of action would be against the employer and not the employee because the discrimination laws only apply to "employers."
All that said, if he ever touches someone without their permission in an agressive manner, including throwing something at them that makes contact, or makes an immediate threat of physical violence, then that person should call the police and file a criminal complaint and might even be able to file a tort action against him for any assault. Again though, if he does this at work, the employer will also be a defendant, especially since they know of his tendencies.
Ultimately it is up to the senior partners to discipline this partner ( I assume). If they don't respect their employees enough to do that, then it might be time for the employees to find a firm that does.
Please feel free to ask for clarification of my answer or a related follow up question simply by replying to my answer. That comes as a part of the service I provide in exchange for the fee you have agreed to pay for my services. Also, please let me know if you are having difficulty processing your Accept/Submit.