Dealing with a serial cheater

I'm disappointed to find that a student for whom I developed some sympathy early on has a history of cheating in my course. I've reviewed his PhD level final assignment (after receiving an email less than 12 hours before the deadline asking what to write about). As I mentioned in the comments section of someone else's blog, I particularly like the branch of German theoretical critique that the student has adopted. It's amazingly in synch with a German social scientist whose work can be found online. So in synch that the student uses 98% of the same words in his assignment.

As a new prof, I'm learning the ins and outs of my school's policy on academic dishonesty. I'm documenting away, meeting with the student and the dean and backing everything up. I've been warned by other profs that my university is very pro-student, and will often find in their favour. I hope, as there is evidence of months worth of dishonesty, that this will not be the case. To have the uni find against me in my first case of plagiarism would likely put a sour spin on what has been a great teaching experience so far.