Combining what was known about Daniel Mustard at the time he stabbed 87-year-old Ruby Andrews to death in April 2009 with what we learned about him afterwards, the feeling here is that the 50-year prison sentence meted out this week was richly earned.

Attorneys for the 19-year-old South Kitsap resident agued their client was insane when he committed the crime, blaming his condition on a long history of substance abuse.

But Kitsap County Superior Court Judge Leila Mills, in pronouncing his sentence, noted Mustard was obviously aware of his actions.

“It’s clear to me that you knew what you’d done, because you tried to hide what you’d done,” Mills said, noting that Mustard cleaned off the knife and changed his clothes, both acts calclulated to make identification difficult.

Obviously an insane person — by definition someone incapable of distinguishing between right and wrong — wouldn’t try to hide guilt they didn’t comprehend.

The incontrovertible logic of that observation, in fact, prompted Mills to take the insanity defense off the table before the juror’s were able to even consider it — which meant the prosecution’s star witness delivered a $100,000 performance for nothing.

Psychologist Park Dietz, who has testified at such high-profile murder trials as those for Susan Smith, Jeffrey Dahmer, the Unabomber and the Menendez brothers, was retained by Kitsap County Prosecutor Russ Hauge at a cost of $600 an hour to evaluate Mustard’s mental state.

And by all accounts, Dietz’s testimony was impressive — but ultimately unnecessary, since the jury didn’t get to consider the insanity issue and Mills apparently didn’t need a lot of psychological mumbo-jumbo to help make up her mind.

In the end, Mustard got the verdict he deserved and Kitsap County taxpayers got a $100,000 bill for killing a fly with a sledgehammer.