legal eagle 
(also legal beagle)
noun informal
A lawyer, especially one who is keen and astute.There is much admiring of young legal eagles, studying of wizened magistrates and cowering from unrepentant defendants to be done....
- And as if the company didn't have enough lawyers already, Rambus is currently advertising for yet more legal eagles here.
- I'm sure the legal eagles who reviewed all this know what they're doing, but this has made me just a little bit curious about exactly how libel laws work.