By the way, talk of a hostage situation and negotiations reminded me of a great book I read a while ago, written by a former Las Vegas hostage negotiator. Each chapter is a different hostage situation that he was involved with. I found it a very conversational reading style, with interesting notes on what worked and what didn't.
I'm not sure if linking to it on Amazon is okay but you can search for it there, and if you happen to have Kindle Unlimited you can borrow it for free. It's called HELD HOSTAGE: Negotiating Life and Death for the Las Vegas Police Department, by Dennis Flynn.