Head to Illium and speak with Liara. She'll tell you to go down to the transportation area to speak to Officer Dara, who'll take you to the spaceport. Speak to Detective Anya, and from there, trigger the mission, which is not that hard. Once you finish the mission, the achievement will appear.
NOTE- Once you go to the spaceport, you will not be allowed to return to the rest of Illium or the Normandy until you complete the mission.