This is a story related achievement which will unlock with natural story progression.
Search for a pencil and the other items Holmes asks for, then go over to the map and place the bodies of each working girl in the following locations:
29 Hanbury Street
After you place the victims you will now need to draw a line between the following locations:
Miter Square > Buck's Row > Dutfield Yard's > 29 Hanbury Street
After Holmes has finished talking you will then need to draw a line from:
Dutfield Yard's > Miter Square
To finish off the map you will need to draw a ellipse around the Dutfield Yard and Miter Square. Click in the middle of the bottom line and stretch it out. Next use the comps to draw a circle around Goulston Street and colour it in using the shading tool.
Once you complete this task the achievement will unlock.