FORT SMITH – A Fort Smith man was sentenced to 36 months in prison followed by three years of supervised release on one count of Mailing a Threatening Communication. The Honorable Judge P.K. Holmes III presided over the sentencing hearing in the United States District Court in Fort Smith.

According to court documents, On June 25, 2021, the Sebastian County District Court received a letter from David Daniel Dieringer, III, age 28, threatening to blow up the Fayetteville Federal Courthouse and the White House. The letter stated that if the recipient did not communicate the threat, that they would be killed. The return address was an address used by the Sebastian County Adult Detention Center where Dieringer was an inmate at the time.

Dieringer was interviewed and admitted to sending the letter, and stated that if given the opportunity, Dieringer would carry out bombings of both locations using a pressure cooker bomb. Dieringer also described how to assemble such a device. On July 11, 2021, Dieringer placed a letter addressed to the White House in the Sebastian County Detention Center inmate mail system. The letter addressed President Joe Biden and stated, “When I get out of federal prison, I’m going to blow up the White House.” Dieringer was later interviewed and admitted to writing the second letter as well.