Edgar Allen Poe (62)
I think, his short stories are still one of the best in this ganre. Dark Mystery.

GK Chesterton (14)
One of the best mystery writers

Wilkie Collins (34)
Charles's Dickens pal, author of many influential works, mystery and otherwise.

Anna Catherine Green (12)
Another best-selling early mystery writer.

Charles Dickens (18)
Famous not with his mystery books though.

Gast-on Leroux (3)
Author of Phantom of the Opera.

Maurice Leblanc (10)
The author of the famous Arsene Lupin series, a gentleman burglar type who was the rival of Hornung's Raffles early in the 20th century.

Agatha Christie (15)
The best Mystery writer ever.

E Phillips Oppenheim (14)
A prolific mystery writer.