1) You have legal recourse, in that if you have been threatened as you say, you can press charges against him, seek a protective order, and possibly even sue him for making terroristic threats or harassing you.2) However, the law does not require the company to take action when employee A threatens or has a conflict with employee B; a company is allowed to not do anything and leave the employees as they were.3) However, the above said, the company *should* do something, since if anything does happen--e.g. you are attacked or injured--you could hold the company liable for negligent supervision, since they had warning but wrongfully failed to act. This is therefore a situation where you cannot proactively make the company take steps, but you can hold them liable after the fact.