'defense of others' is too limited in practice, bob the serial killer should be killed in this hypo

Unfortunately, I've only been provided 3 rounds to do this, so I'll have to make them count. I accepted this not because I agree with this side, but because I was bored. So here goes.1. Morality as categoricalAs Kant argued, it only makes sense to think of morality as universally applicable in terms of its principles. Pro obviously sees the act of ending a human life as reprehensible, evidenced by the position that it would be morally permissible to end the life of Bob because he will kill again. Pro places value on the lives of these individuals and views saving their lives as a moral imperative. Yet, Pro does not apply this same moral calculus to the actor in the hypothetical. If it is wrong to, as Pro implies, end the life of another, then it must be wrong to end the life of the serial killer. The act of ending another's life in and of itself is what's morally reprehensible; the moral rightness of the action isn't contingent upon the character of the individual. Pro will make the argument that, in this scenario, it is ok to kill because the act of killing actually saves lives, but Pro must first refute the notion that killing in and of itself is wrong without damaging the claim that these lives should be saved.2. Weighing Moral PrinciplesEven if you don't buy the argument that killing is categorically impermissible, we must assess when it's ok to kill. The principle of "imminent danger" to another's life is important with regard to western liberal legal history. It respects the ideal that everyone has a moral right to be tried for his/her crimes rather than being judged arbitrarily by park-going vigilantes. Pro doesn't even provide evidence that this person has committed the crime. We are forced to assume some sort of transcendental knowledge of the crimes committed, an uncanny ability to identify such a killer, etc. Even if we can be sure that this is indeed Bob, we shouldn't deny him of a fair trial. A sense of security in society is achieved b/c we know that, no matter what we're accused of or how much others wish to invoke personal retribution by taking matters into their own hands, we have the opportunity to defend ourselves in court and present evidence to fight the prosecution. It is in defense of this fundamental principle of a right to a trial that forbids us from killing based upon mere speculation.It is not a defense of homicide to claim that Bob will probably continue killing. Morality isn't a game of probability. It is categorical, or at least principled in its founding. Few modern philosophers will take a utilitarian approach to moral issues & fewer still will claim to be act utilitarian. This goes beyond that. This is utilitarianism based upon the probability of preserving external moral rights of speculative victims w/o full knowledge that your conscious act to murder someone will actually have the desired effect, namely saving lives. If there is a principle to rule in this situation, it is "do not end the life of another human being, especially when unprovoked".The reason that the principle "only when imminent danger is present" exists is to defend the immediate rights of those threatened by someone like Bob. If we can effortlessly observe such a situation which presents a clear and present danger to the life of another, it is ok to intervene. Otherwise, we cannot be said to have enough information to be able to come to the conclusion that killing in an act of vigilantism is the best possible way to resolve the situation. Better than calling the cops even though he might get away. Better than not killing someone because it's likely that he'll kill again. Better than aiming for Bob's legs rather than killing him. This is information that we as imperfect beings can never have access to. We can not make value-claims based upon probability with such imperfect information.But a thought experiment to more accurately envision a brighter line between the principle of acting when someone is in imminent danger and acting when someone will be in danger would be in order. I'll remove the history of murder as to remove biases from readers, and I'll lengthen the timespan, though I won't diminish or augment certainty on the part of the actor. Suppose there is a young boy named OJ. You are quite certain that, within the next few decades, OJ will kill his wife. He will do so deliberately and, if you kill him now, you can stop this from happening. Why do we intuitively think that it is wrong to do this? It appears as though it is the timespan between our actions and OJ's potential actions. But, as Pro would argue, it is preferable that we end the life of OJ now so that this event does not occur rather than seeking one of many alternative routes. Even if there were none, societal morality would be a difficult framework under which to reconcile the principles of proportional punishment/justice through the system and the notion that we believe this person will kill eventually is enough to kill them. It's borderline thought crime in the sense that someone is served retribution not for their actions, but for what actions may or may not occur in the future. For the same reason that the government can't search your car because you are a known stoner and have smoked before, the government can't kill you because you are a known killer and have killed many times before. Conceding that arbitrary citizens have that moral right as well? It's beyond a long-shot.The bright line exists between what you can prove in a sensory manner (e.g., literally watching Bob aim a gun to someone's head) and what you extrapolate from past actions. Imminent danger is always a good principle, as it prevents a past mental state or action from having any bearing on what rights you have in the future. Killing someone is not something to be taken lightly. It is a punishment of infinite proportions. This is why we ought only allow such a killing morally in the most extreme and certain of circumstances. 3. Obligation to Obey the LawIn hard cases such as these, we must still default to our obligation to obey the law. This is indeed a moral obligation, as we trade many liberties to protect certain rights that we deem fundamental. The United States & other western liberal democracies are founded upon, in part, the principle that the state may not strip you of any further rights without a reason to do so & that this must be determined in court by a legitimate arbiter, namely a judge. We benefit greatly from the notion that others respect our negative rights by carrying out their correlative duties unequivocally. In a hard case such as this, where one's right to a fair trial is placed on the scale against another person's right to life and a speculative threat to that life, we default to the principle that the government ought to have a monopoly on coercive force as to ensure that only a state which is sanctioned by the people may act to limit the liberties of the people. "What we ought to do in any given situation depends on the balance of moral considerations. The fact that we may already have a moral obligation to do something does not mean that, from the point of view of morality, nothing is added when the same action is made the subject of a legal obligation. In a situation in which we are confronted with conflicting moral obligations, the fact that we are under a legal obligation to choose one particular line of action may, from the moral perspective, without regard to the sanction imposed by the law, tip the balance in favor of that particular line or action."[1]Even though we are speaking of the morality sans legality of killing Bob, the legality of an action is so inextricably linked to its morality that it is not something we can ignore. This adds additional weight to my argument as well as tipping the scales in my favor should the case be too hard to judge otherwise.[1] http://scholarship.law.duke.edu...