You need to purchase the Naked City DLC in order to get this achievement.
Find and inspect all of the narcotics in Julia Randall's apartment.
At the beginning of the case you arrive at the murder scene and have to search for clues. Make sure to check for all of the narcotics in the apartment to unlock the achievement. Here are the ones you need:

*Morphine which you acquire automatically.
*Empty morphine surette. On the bottom floor of the apartment complex you find this in a trashcan.
*Sleeping pills in Julia Randall's bedroom at the foot of the bed.
*Benezedrine Prescription. On the right hand nightstand in Julia's bedroom there is a round pill container. Inspect it for more sleeping pills then push A to inspect further and find the prescription.