Deterrence is not the only purpose of punishment under the law. There's also a matter of justice. The latter demands a very, very harsh penalty in this case.
What do think would 'help the issue' going forward?
aside from the rare chemical imbalance, most data is fairly clear that systemic dynamics are primary factors in crime (and especially in sentencing/punishment)
just punishing while being blithe to political/systemic factors that at least contributed (if not being the driving factor) to the crimes, just perpetuates the ****** up dynamics
yes, removed the dude from society, BUT work to make sure the likliehood of the 'next' crime lessens