Anyone caught cheating at my university, especially if they lied about it, was expelled more or less immediately.

Pretty much my observation. Professors could give lenience and a warning by not reporting it, but if they reported it to Academic Affairs, the Provost would probably end up throwing them out.

One time, several people cheated on physics homework (apparently in a very obvious way), and the professor took fifteen minutes out of the next lecture to basically say "you know who you are, you got a zero, and if I see it again, I'm going straight to the Provost."