Mystery novels, especially cozy mysteries, are relativity violence-light despite the fact that at least one person gets murdered by the end of it. For many writers, they skip over any controversy and just have someone come upon a dead body. Violence is described in coroners reports and such, but other than that all the violence is done off the page.
However, for many writers who want to kill off a favorite character, leave a clue in the description of the murder, or for people who want to stretch their writing limbs they write the murder or violent scene out in full. This begs the question; how much violence is too much violence for a mystery novel?
It’s not a war novel or a high action book, but too little violence and the writer might not have written it at all. To make the violence effective, but still tasteful, ensure that we see everything but the blow.
Most old-time mystery movies and shows are the best example of this in action. For most of them, we see the killer preparing his weapon of choice, we watch the gun aim out of the shadows in a gloved hand for instance. We see the intended victim going about their life without care until they see the killer. Shock grows across their face, and then we hear the gunshot or the stabbing sound, followed by the body hitting the floor or the killer leaving.
Yet, even though we don’t see the knife piercing flesh or the gunshot knocking someone backward the suspense is still there. It might sound counter-intuitive, but if you focus on the buildup and the aftermath well enough, the reader won’t care that the moment of the murder itself was left unshown.