*Spoilers ahead*
After completing Case 7 - 2 (Where you have to collect the time bombs in the maintenance tunnels) there will be a cutscene where Frank gets rid of the bombs and Brad fights Carlito. After this cutscene go back into the maintenance tunnels and take the first right then the next left then finally the next right (this is also how you find the maintenance tunnel key so if you got the key before then you'll know where to go) This will activate another cutscene with Brad and once the cutscene is over, he will be 'zombified'
Simply take a picture of 'zombie Brad' and achievement unlocked.
Any feedback is welcomed
