There are 4 side quests for Keith David, all of which are completing activities and targets. These quests, and their rewards, are:
Campaign Trail of Destruction - Dubstep Gun
Executive Orders - Unlimited Sprinting
The Simulation Recognizes... - Double Hacking Time
Supreme Justice - Roddy Suit
I did these just after meeting the AI, but before giving him a CID body. I believe this is necessary, as Supreme Justice starts with a rift. The achievement should pop at the Roddy Suit unlock screen.