Can a manager be bullied by an associate when Sr management refuses to allow the associates conduct be addressed

Wow. So management took the side of this insubordinate associate over you. Not good. You probably need to look for another job confidentially. Management may not understand that threats at work can result in orders of protection. Yes. Just like with a domestic situation, if this associate threatens you again you could proceed to the police, file a report that you reasonably believe you are threatened, the police might investigate the same day. They refer the report to a judge if you wish and a judge could enter an order of protection almost the same day. One thing New York takes very seriously is threats of violence against anyone, especially at work. I have see employees make jokes about coming to work and shooting people be fired. Everyone knew it was a joke. Same for employees making jokes about never going to report incidents to human resources or bodily harm will occur. Employee is terminated and denied unemployment benefits even though everyone at the bar thought it was just a joke. I have also seen managers get fired for placing their hand on a clerk. Clerk runs to the police, files a report, and a judge enters an order of protection preventing the manager from being within hundreds of feet of the clerk, essentially firing the manager from their job. If you reasonably ever again feel threatened, there is plenty of case law supporting New York judges who believe people or employees feel threatened and enter emergency orders to protect them. If you feel unsafe and HR will not protect you, go to the police. But you really should start looking for another job because if they do not have your back here the future will likely not be good either. Good luck. FYI - seems very unusual for upper management to bring back an employee with such behavioral issues. Your company may end up in heavy litigation if this associate causes harm in the future and they were warned. Bringing them back does not appear to have been the right thing to do per facts as you described them.