Not looking at the crime, let us think of it this way.
Say that you do not have SRS. In the states that means you are put into a prison based on your genitals. So basically they have a woman living in a men's prison. Often they segregate prisoners who are more than likely to be attacked by other inmates. This could mean serving an entire sentence almost completely in solitary. How does that impact mental health? If we are not going to execute a prisoner and instead hold them for life, are we not responsible for their quality of life? If so then what kind of quality would we want to offer?
I will not excuse murder. Self defense killings are one matter but murder implies that there was another option and that was leaving the person alive. To take a life is the most dramatic thing you can do as a human being. Whether by science or miracle, we are a rare species in the universe and when a life is snuffed out prematurely, a bit of the wonder in the creation disappears.
