Some form of agent-relative constraint against the killing of innocent personsis a central principle in deontological moraltheories. In this article I make two claimsabout this constraint. First, I argue that somekillings of innocents performed incircumstances usually not taken to exculpatethe killer are not even pro tanto wrong.Second, I contend that either there is noagent-relative constraint against the killingof innocents or this constraint has a verydifferent shape from that which deontologistsnormally take it to have. My defence of theseclaims rests on two propositions. First, inkilling someone one may actually prolong thatperson's life. Roughly, life-prolongingkillings are possible, because to kill someoneis to perform an act that causes someone'sdeath and it might well be true that, had onenot performed this act, one's ``victim'' wouldhave died earlier. Second, all other thingsbeing equal, killing and causing a person to beunconscious are morally equivalent. Both ofthese propositions are defended in thearticle.