Prosecutors have released disturbing new details about the beheading of a man by his son in a suburban Philadelphia home.
Justin Mohn, 32, allegedly shot his father, a federal worker, before using a knife and machete to decapitate him.
He then posted a rambling video on YouTube advocating the torture and killing of US government employees.
The video was on the site for several hours before it was taken down, authorities said.
Bucks County District Attorney Jennifer Schorn said during a news conference on Friday that Mr Mohn had a “clear plan” when he killed his father – 68-year-old Michael Mohn – and then drove to a National Guard training centre two hours away. He had hoped to stir up a rebellion there, she said.
“This individual was acting with clear mind, aware of his actions and proud of his consequences,” she told reporters.
After the killing, Mr Mohn posted a 14.5-minute video on YouTube titled Mohn’s Militia – Call to Arms for American Patriots.
In it, he appeared to read from a script before picking up his father’s severed head and showing it to the camera, according to a police report.
He offered a bounty for the killing of top federal officials, read out the home address of a judge, and urged people watching to torture and kill federal agents. He also called his father a “traitor” and expressed anger about “far-left woke mobs”, immigrants and the LGBTQ community.
Mr Mohn’s father worked for the Army Corps of Engineers, a branch of the US Army.
Police said the video was live on the internet for about five hours. It was viewed more than 5,000 times.
“It’s quite horrifying how many views we understand it had before it was taken down,” Ms Schorn said.
YouTube said in a statement that the video was taken down for violating its rules against graphic violence and violent extremism, and that it is working to remove re-uploads of the clip.
The platform, which is owned by Google, has not said why the video remained live for several hours.
Michael Mohn’s headless body was found by his wife in the bathroom of the family home, prosecutors said. The head was found in a nearby bedroom. It was wrapped in a plastic bag and placed inside a cooking pot.
Justin Mohn was arrested with a loaded 9mm handgun at a National Guard base in Fort Indiantown Gap, Pennsylvania, several hours after police were alerted to the attack on Tuesday evening.
The base is about 100 miles (160km) from the Mohn family home in Levittown, a Philadelphia suburb.
Ms Schorn said that Mr Mohn bought a handgun the day before the killing and even gave up his state-issued medical marijuana card, so that he could buy the firearm legally under federal law.
Authorities said Mr Mohn drove on to the base and scaled a fence hoping to encourage the National Guard to start a rebellion against the US federal government.
Prosecutors say he had held several jobs after graduating from Pennsylvania State University, but he was unemployed and living with his parents at the time of the killing.
He was charged with murder, abuse of a corpse and possession of an instrument of crime and has been ordered held without bail.
