Hitman 3’s Death in the Family mission can be completed in a number of amusing ways, but the undisputed highlight of this assignment is the ability to pose as a private investigator and attempt to solve the murder of Zachary Carlisle.

You might suspect that a “Whodunnit?” case built into a Hitman game would be somewhat watered down, but the truth of the matter is that Death in the Family’s murder mystery is one of the better examples of this format in video game history (and my personal favorite since the best quest in The Elder Scrolls franchise). In fact, it’s quite easy to miss vital clues and walk away with the wrong impression of who the murder actually is.

So who really killed Zachary Carlisle? Before we answer that question, here’s a rundown of the things you’ll need to do in order to properly close this case.