You could report the boss to the police, for making a threat against you; depending the exact circumstances, they may or not do anything, but at least it will be on record.You do not have recourse to a lawsuit; you haven't suffered any actual loss or injury, so there'd be nothing to sue over. Lawsuits compensate people for injury; a single threat, by itself, would almost certainly not justify monetary compensation in a context like this.If the threat, or  the lack of action of management and HR, grew out of your membership in a protected category (e.g. it's because of your race, sex, religion, disability, age over 40), then you might have a claim against the company. Otherwise, you probably don't--there's no actual requirement that employers be fair to their employees.