Here is the full list of all 41 Lamplight City achievements.
Completed the game
Correctly solved every case
Confronted the Justice Killer in his own home
Told Adelaide the truth
Discovered the truth about the cooping scheme
Accused Tom Puffin of murdering Ronan L'Espaye
Read every book in the game
You voted!
Told Patrick a story
Accused Roger DeVay of murdering Desiree Lathan
Gave Charlotte Robineaux a music lesson
Successfully located Linda Walker
Accuse Linda Walker of kidnapping the Harris baby
Fixed the boiler without any help
Told Angela Maxwell about your problems
Learned about Mrs. Davis's hobby
Revealed Madame DuPrée's true nature
Read Madame DuPrée's poems
Got kicked out of Sabine Martin's apartment
Kept your promise to Mrs. Hanbrook
You're so annoying
Played a familiar melody
Accused Albert Martin of Madame DuPrée's attempted murder
Accused Juliette Montgomery of Madame DuPrée's attempted murder
Accused Guy Dumas of Madame DuPrée's attempted murder
Spoke with Roland Deveraux
Accused Malcolm Harris of kidnapping his own son
Accuse Arthur Devins of kidnapping the Harris baby
Showed Desiree's ashes to someone who wasn't Dr. Edwards
Tricked Jonas Usher
Concluded that Desiree Lathan's death was due to spontaneous human combustion
Accused Margaret Andrews of murdering Desiree Lathan
Accused Jimbo of murdering Ronan L'Espaye
Sang a popular drinking song
Checked yourself into Riverview Asylum
Ended up in jail
Declared a case unsolvable
Found every single clue and document in the game
Played through the entire game without opening the casebook
Every friendship has one
Eavesdropped on every conversation