Mystery Case Files: Prime Suspects is the second instalment in the Mystery Case Files franchise and was released in April 2006. The player is tasked with investigating the disappearance of the Queen’s Hope Diamond in Capital City. Mystery Case Files: Prime Suspects added items that players have to discover to unlock later levels (such as finding a battery to power a flashlight). Characters also became a more prominent part of the series with the investigation revolving around multiple characters with different personality ‘quirks’. Every time the game is played, the suspects and culprit are different.