Suicide

[bennyboy]

Suicide gets a moral pass because the proverbial knife you are sticking in the proverbial back, is your own back and knife.
People who commit suicide aren't doing so to cause others harm. They are doing it to end their own personal pain and suffering.

Someone who decides to murder someone else isn't doing it for the same reasons as someone who is harming themselves because they are hurting. So I should point out that you didn't speak on the subject of mercy killing. Just misplaced anger and harming another vs suicide.

I disagree with your assessment.  I think many murderers have no foreknowledge of what they will do, and when they lash out, it's not so much at an identified person as at a world that seems infinitely hostile-- due to bad chemistry, out of control hormones, drug use, etc. I think very, very few people "decide to murder."