LEVITTOWN, Pa. — A Pennsylvania man on trial for the brutal killing and beheading of his father testified Wednesday that the slaying was “Plan B” after a failed attempt to place his father under citizen’s arrest for alleged treason.
Justin D. Mohn, 33, took the stand in his own defense during his bench trial, where he faces charges of first-degree murder and other crimes related to the January 30, 2024, killing of his father, Michael F. Mohn, in their family’s Levittown home.
Mohn told the court he believed his father had made false statements in a federal civil case and committed treason. Claiming political differences, Mohn said his father, a federal employee with the U.S. Army Corps of Engineers, tried to stop him from becoming a Trump-like political figure.
According to Mohn, when he announced his intention to arrest his father, the older man resisted and reached for the gun — prompting Mohn to shoot him in the bathroom.
“Unfortunately, he resisted,” Mohn said. “I was hoping to perform a citizen’s arrest on my father for, ultimately, treason.”
Court evidence included a notebook labeled “Plan B,” with chilling entries like “Boom” and “Slice.”
After shooting his father, Mohn beheaded him using a kitchen knife and machete, later posting a 14-minute video of the act to YouTube. The footage, which included anti-government rants, remained online for several hours before being taken down.
Mohn claimed the shocking act was intended to send a message to federal workers and push for his political demands, including debt cancellation and mass resignations.
“I knew something such as a severed head would not only go viral but could lessen the violence,” he testified, saying it was not meant to cause trauma to his family.
His mother, Denice Mohn, wept in court during his testimony. Earlier in the trial, she had said she and her husband financially supported Justin, and that police had previously warned them about his violent anti-government writings online.
Following the killing, Mohn was arrested after scaling a fence at Fort Indiantown Gap, the state’s National Guard headquarters. Authorities say he had a USB with federal building photos and bomb-making instructions, and was calling for the overthrow of the U.S. government.
Prosecutors called the act “cold, calculated, and organized”, describing it as a form of intimidation against federal workers. They highlighted the brutality of the crime and Mohn’s far-right extremism as central to his motive.
Michael Mohn was remembered as a devoted father and respected engineer.
During a previous competency hearing, Mohn was found fit to stand trial despite having written to Russian officials, including a letter to Vladimir Putin, in which he apologized and offered to defect.
The trial, which includes graphic evidence, is being conducted without a jury, with a judge presiding alone.
