Avi K,
Moreover, various and sundry implements can be used as weapons for both murder and suicide.
This is a variant of the old, “why bother putting up a fence along the bridge” argument. After all, someone bent on suicide would just find another way to do it if there were a fence blocking the way off the bridge. Research has shown, however, that that is not true. Suicide and many murders are impulsive acts, even if they are planned out over a period of time. A fence, a question like “how are you feeling today?” or waiting periods/background checks can be crucial to snap someone out of impulsive and reactive thinking.