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