Speak to Elling Trias in Stormwind.
That Marzon would be contacting a member of the Defias and have ties to Lescovar...
Having killed VanCleef and Thredd, it would be hard to see Lescovar brought to proper justice, as your evidence is nothing without their testimonies. That is not even considering the fact that Lescovar is a noble and well connected. It effectively makes him above the law.
You'll need other help. I loathe to do so, but there is someone I know that will aid us. You'll find Trias in the Trade District of the city.
You're kidding? Shaw wants my help again? Of all the nerve...
The Defias Brotherhood, you say? Well, you're certainly the bearer of wonderful news, aren't you? Next you're going to tell me that Deathwing is still alive and attacking the city.
All right, tell me everything from the beginning. And don't leave out something you think might not be important. I need to know it all.
Upon completion of this quest you will gain: