Consistancy, and justice, requires similar sentences for similar crimes. There are no similar examples of life sentences for criminality of this nature. My guess he'll get somewhere between 8 and 20 years, which is what a defendent who doesn't look odd would get.
It would be useful to know what sentences similar circumstances have generated in the past, before judging if the prosecutors are too harsh.
He was offered a plea deal, but turned it down, choosing to go to trial, despite the mountains of evidence against him.
I have a hard time being sympathic, sorry.