The first time you're in Detroit you can go to Double T's apartment as a side mission. I shot the guard outside with the tranquilizer rifle in the head and he showed up as dead. On the wiki it says that he actually is dead and it will void the achievement. Is this true? Thanks for any help.
30K GS Reached 11/18/2012 with
Lone Wolf Legend 90G
Completed the Campaign solo on Legendary difficulty