Expensive Penalty

A young man (probably deranged) climbed up on the roof of his vehicle, and took aim on a Longmont police officer. Fortunately, when he fired, he completely missed . Found guilty on two separate charges related to this incident, he has been sentenced to a total of 72 years in prison. Taxpayers will be paying out thousands of dollars, and he may spend most of the rest of his life in captivity. I'm in no position to judge whether he should be in a mental hospital, but this sentence seems to meet the test of "cruel and unusual punishment".' How can this punishment be said to fit the crime?