As a side note, although your raise is five months late, you should still raise the point that you expect it to be provided retroactively. Joe gets along well with the boss, but everyone else in the office is afraid of him. He has a violent temper and swears constantly. I told my boss that we don't feel safe with Joe working here, but he refuses to do anything. In fact, he thinks the whole situation is funny.
Every threat is deadly serious.
You need to take immediate action to deal with this matter. You and your associates should bypass your boss and go directly to the most senior-level person you can access in your company and describe what is happening. Companies have a legal obligation to provide a safe work environment, and there is already major exposure because your boss has been advised of the problem. Someone in a topside position needs to investigate this matter right now. Threatening an employee with bodily harm warrants immediate and severe managerial action.