Criminally negligent parenting causing the death of a child is bad. It should probably be a felony. It shouldn't, however, be first degree murder, which is what it is in Colorado.
Bad parents are not irredeemable criminals who are a never ending menace to our society that can only be addressed through the death penalty or life in prison without possibility of parole. But, those are the only punishments allowed for a conviction of first degree murder.
Leaving a five-month baby boy alone at home for up to seven hours while you go drinking is criminally stupid and has catastrophic consequences. But, this doesn't mean that you should be counted in the same ranks as serial killers, murderous terrorists, and people who gun down tellers while robbing banks. Yet, in Colorado, child abuse causing death, with "abuse" defined rather broadly, is first degree murder.
Colorado's law in this area is disproportionate and also exceedingly expensive to the state while providing no compensurate protection for the public. It may be appropriate to put someone who does this in prison for a few years and have their parental rights to their other children terminated. Is justice really better served by putting a bad dad in jail for five years instead of fifty (at a cost of $1.5 million of public funds, give or take). But, locking away a twenty-three year old for life is gross overkill, and this disproportionately high penalty also heavily burdens the right of defendants in often ambiguous cases to tell their side of the story to a jury at trial.
If Colorado simply make the effort to make most of the excessive sentences in the criminal code more proportionate to the crimes involved, it could spend less on criminal justice without creating the kind of public risk that purely budget driven early releases of inmates would cause.