My experience of Violence threats - and a happy ending
My employer decided to withdraw 24 hour access to the headquarters building and have no security on site.
A few weeks later I had a major problem which would have meant 3 figures of staff unable to work on Monday morning. Failed to fix it within the new working hours. Notified security I was going to overrun. It turned out that the Facilities management management had given the security staff no instructions whatsoever about what to do in an emergency situation, and no escalation, so the poor chap - and of course security guards are rarely chosen for independant thinking or given significant authority - had absolutely no idea what to do. So he fell back on threats of violence if I didn't vacate the building with the work incomplete.
Fortunately my line management was contactable, so I got them to get things sorted out, and some while later a very apologetic - to say the least - security guard came to see me to confirm I was clear to stay until the work was finished.
The happy ending? On Monday I passed up through my management that I wanted no repercussions or action on the security guard at all, because I felt the fault was completely with his line management. As a result I was thereafter in extremely good odour with building security, which proved to be very handy over the next few years.