MIDDLETOWN TWP., Pa. -- Note: This story includes graphic descriptions some readers may find disturbing.
More details about the man accused of beheading his father in Bucks County, Pennsylvania are being shared Thursday.
Neighbors in Middletown Township say they frequently saw 32-year-old Justin Mohn exhibiting odd behavior in the neighborhood.
Neighbors say they noticed changes in Mohn's behavior several months ago. While they say it was nothing violent, it was enough to make them uncomfortable. One of them even ended up calling the police.
"He just started acting funny over the summer. I made a couple calls to the police department because he was sitting right there on that culvert thing and staring at my house constantly. I thought that's kind of strange," neighbor Bart DeHaven said.
When asked if he felt threatened, DeHaven said "no."
"But it's just weird for somebody to stay seated right there, stare straight at my house. You know, when I would come home, he would just pick up and move -- weird," he said.
Mohn is now facing charges after being accused of beheading his father, Michael Mohn, and posting a gruesome video to YouTube while holding up the severed head.
Police say the victim's wife discovered his body around 7 p.m. on Tuesday at their home.
Police arrested their son a couple of hours later, about 100 miles away by a National Guard base in Fort Indiantown Gap in Pennsylvania.
Another neighbor said she opened the YouTube video without knowing how gruesome it was.
"I totally screamed, like, somebody sent the video, and I opened the video, and I was like, 'Oh, my God, That's the guy that, you know, I see every day that I knew something. You know, something was unhinged with him,'" Carrie McCarthy said. "So, a lot of us, especially the people that walk the dogs, we've seen him. He's a fixture in the neighborhood. He would just walk around, always have his water bottle. And he would stop in random spots and just light up a joint and just start smoking."
In the 14-minute-long YouTube video, Mohn referred to himself as a militia leader, threatened federal officials and called his father a traitor to the country for being a federal employee.
ABC Philadelphia affiliate WPVI has learned that 68-year-old Michael Mohn was an engineer for the U.S. Army Corps of Engineers Philadelphia District.
"We are deeply saddened to learn of the tragic death of our teammate Michael Mohn. Our thoughts and prayers are with the Mohn family and we are focused on supporting our grieving employees at this time," the U.S. Army Corps of Engineers Philadelphia District said in a statement.
The YouTube video was viewed 5,000 times before it was taken down.
A YouTube spokesperson told WPVI that their team is closely tracking to remove any potential clips of the video that might be re-uploaded in the future.