PITTSBURGH (AP) – A federal judge in western Pennsylvania has rejected a former Allegheny College professor’s bid for leniency in a child pornography case.

Fifty-eight-year-old Kirk Nesset resigned from the Meadville college, about 90 miles north of Pittsburgh, after he was arrested in October 2014. He pleaded guilty last year to possessing, receiving and sharing child pornography.

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Defense attorneys argued that Nesset has “depleted mental health” and needs treatment rather than a harsh prison term. They argued for a mandatory minimum term of only five years.

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But the Pittsburgh Post-Gazette reports that U.S. District Judge David Cercone ruled Friday that he will sentence the award-winning short-story author to between 12½ and 15½ years.

Federal prosecutors cited what they called the defendant’s “staggering” collection of 540,000 child porn images.

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