Here is the full list of all 46 Detective From The Crypt achievements.
Find grandfather's diary
Put the poison into hot chocolate
Open the governess version
Open the version with Lord Darkday
Open Lady Darkday version
Open the Butler version
Open version with Aunt Esther
Unlock all versions of events
Take a blood test
Scare the butler to death
Help a kind mummy
Help the cat mummy
Listen the audio record
Help the bagpiper
Find all the pearls
Open all safes
Make Aunt Drink
Get sleeping pills from the doctor
Find the use of the dung-beetle
Help Mrs Brown
Help Mrs. Jones
Return the necklace to its owner
Learn the secret of the automaton
Find a use of the figurine
Find the use of soap bubbles
Find out whose button it is
Find Opals
Test Substances for Poison
Help the loser
Discover the secret of the library
Find the pocket mirror
Get the second letter
Find the poacher
Find a pocket watch
Help the Maid
Find the rat
Find Anubis Mask
Open the Sarcophagus
Find Pulcheria
Find family jewels
Find the diary
Find the shackles
Apply magnifier to boots
Apply the magnifying glass on the monument
Meet the Greedy Bride
Get a letter from your great-grandmother