Mysteries of the Past is the title of the fourth season of Criminal Case. It was released on November 17, 2016.
Set in the late 19th century Victorian city of Concordia, Mysteries of the Past serves as a prequel to the previous seasons of the game, with its events purely visualized by Jack Archer as he narrates Charles Dupont's journal to his friends and fellow associates of the Bureau.
- Main article: Concordia
The events of Mysteries of the Past is set in the city of Concordia. It is made up of ten districts, and is home to a total of sixty cases. The Concordian Flying Squad is the featured law enforcement agency that serves the city.
- Criminal Case: Mysteries of the Past, a standalone app for the Mysteries of the Past portion of the game, was officially released worldwide on February 22, 2018.