Just confirming that content restrictions for this jam mirror itch policies and the law. All sensitive content must be clearly and appropriately tagged.
You'd have to get clarity from itch to be sure, but in the case of a murder mystery, a warning at the front of the game and on the game's landing page that the story contains depictions of death should work. Some devs opt to include extra details (usually behind a spoiler tag), of the nature of the violence as well.