I found my coworker slumped over in a bathroom stall. We had no idea what happened to him. He got up and left without telling anyone, then after a concerning amount of time tried to locate him. I knew he was dead the moment I kicked open the door, but not what killed him. He was 40.
People just die, and usually from pre-existing conditions that either haven't been resolved, treated or weren't known. Not everything is gonna be a murder, even if a pool of blood is present. You know how easily you can bleed on certain meds?