I have always considered duress button applications to require a thorough application of people, process and technology measures. If the person or organization is at that much risk due to a threat or hostile action being reported in real time, you don't want to just send a signal without having some means of determining what's doing on before you send security personnel in the door or the police are summoned.
Yet over the past couple of years, I've been involved in a number of site walkthroughs and facility security reviews where a security technology provider had recommended and installed duress buttons, and some or none of the duress locations had video coverage or a means of audio listen-in.
About one-quarter of the facilities visited had never tested the duress buttons since the time of installation--in some cases that had been several years. We have encountered quite a variety of situations, such as more duress buttons than were actually being monitored (an error, of course), missing duress buttons, and so on.
I know that this topic goes beyond video, but I consider video and audio monitoring capabilities important for duress notification applications (whether keypad, pendant or button technology is used).
What are the duress applications that don’t warrant or can’t utilize video? One that I can think of at the moment is a pendant or watch duress button, where video coverage is not 100% throughout the coverage area and no GPS tracking is being used.