I thought about that. While it's true Mr. Sutter is quite popular, and knows many of the other students in other departments, his closest friends are in his fraternity. None are what you might call "the type" to be capable of this.

And Mr. Sutter swears up and down that he had no reason to commit the crime, and absolutely no memory of doing it.

It's easy enough for someone to feign ignorance, of course. However...