A conspiracy theorist who co-wrote a book claiming the 2012 Sandy Hook school shooting never happened must pay $450,000 to a father of a boy killed in the shootings.

The jury's decision followed a ruling in July that James Fetzer and Mike Palacek, who co-authored a book titled "Nobody Died at Sandy Hook," defamed Leonard Pozner, whose six-year-old son Noah was among the 26 victims in the December 2012 shooting in Newtown, Connecticut.

Fetzer, a retired University of Minnesota Duluth professor, was ordered to pay damages. He called the amount "absurd," and said he would appeal. Palacek settled with Pozner last month, but those terms were unclear.

'Back to school':Latest Sandy Hook Promise PSA gives nightmarish look at school shootings

'Remington's nightmare will come true':Gun control advocates savor Connecticut court victory

In the book, Fetzer and Palacek claimed that Pozner fabricated copies of his son's death certificate. Fetzer also alleged that the massacre was "a FEMA drill."

After the ruling, Pozner thanked the jury “for recognizing the pain and terror that Mr. Fetzer has purposefully inflicted on me and on other victims of these horrific mass casualty events, like the Sandy Hook shooting," per the Wisconsin State Journal.

Pozner has previously said that his family has been threatened and harassed as a result of the conspiracy theories leveled against him, including on a memorial website dedicated to his son.

He took action against Infowars conspiracy theorist Alex Jones last year, filing an anti-defamation lawsuit against Jones. Jones, who was banned from Facebook and YouTube in 2018, insinuated that the Sandy Hook shooting was fabricated.

That case is still pending.

Contributing: The Associated Press. Follow Joshua Bote on Twitter: @joshua_bote