This is a story related achievement which will unlock with natural story progression.
After you complete the reconstruction of the murder scene you will then enter the deduction board. Here you will need to piece together the evidence. This list is fairly complex so follow it very carefully.
Deduction Board 1:
Top Three Papers:
Answer 1: A black bonnet near the left hand.
Answer 2: Poorly lit street.
Answer 3: The prostitutes only go down the street to "exercise". Answer 4:The victim was holding her bonnet in her hand at the time of the murder.
Answer 5: The victim wasn't afraid.
Final Answer: P. Nichols had her bonnet in her hand and ready to exercise.
Bottom Three Papers:
Answer 1: No traces of blood on walls.
Answer 2: The Victim had her throat slit.Answer 3: The victim didn't have her throat slit while standing.
Answer 4: A little pool of blood.Answer 5: The blood didn't flow in strong spurts.Answer 6: Dirty and damp groundAnswer 7: He could not have relations on the ground.Final Answer: P. Nichols was dead before being stretched and having her throat slit.
Deduction Board 2:
Top Three Papers:
Answer 1: The corpse was still warm.
Answer 2: No footsteps on the ground.
Answer 3: The Murderer cut open Polly's throat.Answer 4: Victim wasn't dragged.Answer 5: P. Nichols murder took place on the premises.
Middle One Papers:
Answer 1: The tongue is bloated.Answer 2: P. Nichols was strangled.Bottom Three Papers:
Answer 1: The throat was slit from left to right.
Answer 2: The murderer must have been sitting on victim.
Answer 3: The victim has a bruise on the right jawbone.Answer 4: The bruise was caused by hard pressure with fingers.Answer 5: The murder was standing in front of the victim to strangle her.Answer 6: The killer's left hand prevented the victim from screaming
Answer 7: The killer strangled the victim with right hand.
Answer 8: Is murderer right handed or left handed?
Final Answer: P. Nichol's killer is a strong man.