Since Rothbard took for granted that everybody wanted to survive and that rights is a result of that. Wouldn’t that mean that it is OK to kill someone that is taking his own life? Let’s say I see someone that is going to jump off a bridge ans says he is going to do it. Can I shoot him?
No, you can’t shoot him. Firstly, he may change his mind about wanting to die. Secondly, if you consider his life a property right, he maintains the right to his own life until he is dead or expressly gives someone else permission to kill him. Thirdly, it is not right for you to choose his manner of death. The man may prefer jumping off a bridge to being shot by a stranger.
Consider also that it may not be in your best interest to take the risk of shooting him. What if the bullet doesn’t kill him on impact and instead the man endures a great deal of suffering before his death? You would be responsible for that suffering.
The guy wants to suicide, not to be killed. You’re initiating aggression on him.
You would have to get his permission first.
I doubt someone on the verge of suicide is going to do some paperwork. How can others know he gave you permission?
The people charging you with murder would have to prove you didn’t have permission.
I don’t think so. All they need to do is prove you murdered him. It is on you to prove you had permission.
This is why you should be careful before shooting people. It is risky to kill someone even if you are pretty sure they murdered someone. It is a reason to agree to arbitration instead of going vigilante.
Let’s assume that it proven that Person A killed someone, the onus is on him to prove it wasn’t murder?
Bring a third party witness? [:D]
Yes, considering we are saying “it has been proven that A killed B”. This isn’t saying “guilty until proven innocent”. We know A killed B. A now needs to prove that killing B was justified.
Not all killing is non-libertarian. Why shouldn’t the accusers be obligated to prove that it wasn’t justified?
But if I see someone jumping off the golden gate bridge, he has no desire to live, and can therefor not have rights, since rights are reserved for people who want to live only. Can’t I shoot him when he falls?
EDIT: And yeah, the practical application for this is zero, but it’s still funny. 
I didn’t say killing or using coercion is always unjustified. The default position is: killing is wrong. The discussion is pretty pointless without actual situations.
Say B is found slumped over the railing of the Brooklyn Bridge with a bullet in his head. Witnesses saw A walking away from the scene around when the autopsy shows B was killed, and the slug in B’s head is linked to A’s gun.
It is then on A to provide evidence that you either did not kill B or that the killing was justified. If you inject doubt, it should be investigated. For this story there is none. It looks like a senseless killing on A’s part.
Rights don’t come from a desire to live. Think about what you are saying. What if I kill 3 people, and scream that I want to live? No, you can’t shoot him when he falls.
I disagree with “rights are reserved for people who want to live.” If that’s what Rothbard said or implied, then I think he was off the mark. Those who commit suicide or want to commit suicide still certainly have the right to choose the terms and conditions of their death. Even after the person is dead, it is not likely that you would have property rights to their corpse. The only times I can imagine that you would be right in shooting a person when they wanted to commit suicide would be A) the person gives you their express permission to shoot them; or B) the person is dead and you have the clear property right to their corpse.
Isn’t this asking them to prove a negative?
Why?
Yes, it is.
That’s not what I meant, but having life as an end is a requirement for rights, think about it, without it, rights would be useless. Rothbard acknowledges it.
Isn’t asking the accused to prove that it wasn’t murder asking to prove a negative?
No, because all you need in order to prove it wasn’t murder is one thing to justify it. Asking them to prove it wasn’t justified is asking them to find every reason it could be justified and proving it false.
So all the accused would have to say is “I had permission”?