This Achievement is obtained by answering questions correctly when interrogating Felix Alvarro at the Bus Shooting, which is part of the Vice Case Manifest Destiny. Part the way through this case you are required to respond to a Bus Shooting, whilst inside the Hollywood Police Station. Upon arival there is a gunman on a rooftop firing down on a Bus in the street. After the cutscene head left round the back of the building and climb the ladder. Then kill the gunman and collect the evidence from the rooftop where shooter was placed, Most importantly the Sniper's Pocketbook which is found in his pocket, as it will be needed as evidence in the questioning of Felix Alvarro. Then head down where you must speak with Felix Alvarro, the bus driver and ex-marine buddy of Cole Phelps. You must then ask Felix Alvarro the questions below and match them with right responses to earn this Achievement/Trophy.
1.Informed of Coolridge Heist: Doubt
2.Motive for Shooting: Lie (Sniper's Pocketbook)
This will then gain the Achievement/Trophy.