The Supreme Court of Virginia sets the processing fees for the whole state. Courts cannot charge *more* than the max fee they set. But localities (like Fairfax) can charge a fee for the sheriff & court facilites (no more than $10), and a fee for the criminal justice academy.
So I'm guessing the breakdown is:
$51 processing fee:
$10 Sheriff/facility fee
$6 fee for the criminal justice academy
I spent about 3 minutes researching this, so I could be wrong.
http://www.courts.state.va.us/courts/scv/rulesofcourt.pdf (starts on Pg 259)