They are both equivalent acts of destructive abuse. One typically allows the preservation of life, but the ambivalence lies in the fact that the suffering lasts long after the conclusion of the violent perpetration. A rape victim's psyche is deeply wounded, the permanence of that scarring depends entirely on how thoroughly dominated the victim was during the rape. Some can recover. There is a feeling of empowerment one can attain from having survived rape and prospered after recovery. A rape victim may ultimately not only escape their victimization, but gain new power over their life.
But a murder has much more permanence. There is no recovery from murder, though there is often far more understanding for the mindset of a murderer. People can comprehend an unplanned violent murder as an act of rage. The victim's suffering isn't visible to the public following a murder.
As with most things, however, the devil is in the details. ANY rape is not equivalent to ANY murder, you've have to give a specific instance of rape to compare to a specific instance of murder. I mean, I think most people would agree that someone with a flesh hook suspension fetish, into whipping and beating victims during the rape has committed far greater an atrocity than someone who drove by and shot a rival gang member. But by the same token, I believe most people would agree that it's a far greater atrocity for someone to pull the entrails from a teenager and leave them to bleed out when compared to a case of statutory where the parents are pressing charges on a 23 year old who was lied to by a then-17 year old.
Sorry if I've offended anyone with my imagery.