Should I write the scene our leave it a mystery?

I am nghề viết văn a sort of mystery suspense drama. One of my charters is a killer the other is hell bent on proving that he is the killer. I was thinking about nghề viết văn the charters kill scene mainly in effort to let my readers know how the evidence my một giây character will find later proves his guilt. Our maybe I should let the readers find out when the other character does. What is your opinion? Thank you!