As the co-author of one of the 1990s' most controversial works of scholarship, Charles Murray is no stranger to angry protesters.
Over the years, at university lectures across the country, the influential conservative scholar and author of The Bell Curve says he's come face-to-face with demonstrators dozens of times.
But none of those interactions prepared him for the chaotic confrontation he encountered last Thursday night at Middlebury College in Middlebury, Vermont.
"When The Bell Curve came out, I'd have lectures with lots of people chanting and picketing with signs, but it was always within the confines of the event and I was eventually able to speak," Murray told The Washington Post. "But I've never experienced anything like this."
The demonstrations on Thursday began conventionally enough, with several hundred organised protesters packed into a lecture hall, chanting and holding signs. They ended with Murray being forced to cancel his lecture and later being surrounded by an unruly mob made up of students and "outside agitators" as he tried to leave campus, according to witnesses and school administrators.
