I'm not sure Mab would appreciate just anyone violating the accords without getting caught, but for her Knight?  While she would absolutely punish him for getting caught,  I think it's fair to say she considers it a training exercise in ingenuity and cunning, so long as he doesn't get caught. 

oh, I'm a pizza snob.  I will eat fast food pizza if it's put in front of me out of politeness to my host, but I'm not going to go there myself.
Frozen pizza?  nope nope nope.
So I totally get where you're coming from Mira.

I put "Wicked Faerie" in quotes because I also disagree with the simplistic view of Mab as "evil".  She's cold, ruthless  and apparently driven by logic and reason to an inhuman degree (though she clearly does have strong emotions). But all that just makes her, well, inhuman.  Which she is. 

Fidelacchius burned Harry.  Because the mantle, supernatural "wicked faerie" power was influencing him. 
Yes his grief and anger were feeding it, but the mantle was, if not running things, then it was definitely guiding the details his actions.

Most likely.
In any case, to the original topic,  I think formal charges against Rudy will only be about his behavior inside the day care center, where Bradley and the "grandmotherly" woman are witnesses. 
Given the casualties the CPD likely took?  I suspect they'll be reluctant to get rid of anyone.

What will be interesting is how others react to events from Battle Ground.

Is Bradley going to get the whole story, and if so... well Murphy and Dresden did save his kid, and Rudolph murdered Karrin in exchange for it. How will he handle that? 
Kincaid and Murphy aren't an item anymore, but I suspect he's still got some fondness for her.
Rawlins, if he survived, seems he might have some strong feelings towards Rudolph.
The Alphas were ready to jump Rudolph and Bradley when they were just going to arrest Harry.  What are they going to do to Rudolph for killing their friend?
Legal consequences for Rudolph are the least of his concerns.

For that matter, I suspect that if Harry would have just shot Rudolph,  the sword wouldn't have done anything to him.  Using magic and The Mantle of the Winter Knight made it a different matter.  I could be wrong on that, but it fits.  Angels can interfere with supernatural threats, but not vanilla mortal technology.