His head was never found.
Police accused Matthew Marshall of attempting to use his father's credit card to pay a bar tab after the killing. Investigators later noticed that the condo reeked of chlorine. A forensic examination revealed that blood had been removed from a shower in the victim's bedroom, one his son wasn't allowed to use, the News-Press reported.
Matthew Marshall was charged with second-degree murder, abuse of a dead body and tampering with or fabricating physical evidence in his father's death.
On Monday - after a trial in which Marshall represented himself - Lee County Circuit Court J. Frank Porter sentenced him to life in prison. The judge said that the crime was "without any doubt the most gruesome and brutal murder of my career."
"It is my intent that you never see the sun rise, the sun set or take a breath outside the walls of the Department of Corrections the rest of your natural life," Porter told Marshall.
During his own statement in court, Marshall "rambled about his Fifth, Sixth and 14th Amendment rights," the Daily News reported. He accused the court of interfering with his ability to prepare for his defense and said the jury was biased before asking Porter to "please give me 10 leprechaun life sentences."
"I might need them," added Marshall, who wore a restrictive cloak in court.
Several family members testified, as well, describing Matthew Marshall's tragic decline from promising young man to terrifying killer, according to the Daily News.
His mother, Mary Raveling, recounted how her son used to confront bullies who targeted his younger brother and how he started an online business at one point, the Daily News reported. His life veered off course, she said, after he was almost killed by necrotizing pancreatitis. She described her son as someone who is "high-functioning mentally ill" but argued that he is "not a monster," the Daily News reported.
"We failed," she said. "I failed as a parent to get him the help he needed."
Marshall's unraveling surprised those who knew him well, according to Chris Lappako, a childhood friend. Lappako told Fox affiliate WFTX that his best friend grew up in an upper-class family and attended private school.
"I got the impression that everybody did love each other in that family," Lappako said.
Lappako told WFTX that his friend struggled with alcohol addiction, which began to alter his personality as far back as 2007. A violent attack on another friend followed not long after his drinking and impulsive behavior worsened, according to police reports cited by the station.
"Matt started acting weird," Lappako said. "He was using coded language that a lot of us didn't understand."
"I know another time he went to someone's house and just stood there and stared at them and then left," he added. "So he's done things to intimidate people in our group. I basically informed his family about the things that he was saying, and I didn't hear from Matt after that."
Nearly a decade later, Lappako finally heard from his old friend again, this time on Facebook. Lappako told WFTX that Marshall began sending him messages last year about secret societies and killing terrorists.
"He never mentioned anything about his dad; I just know he wanted to kill terrorists and I thought he was just joking, drunk, and on social media saying things he would regret the next morning and delete," Lappako said.
When Lappako heard about Marshall's arrest and his father's gruesome death, he had no doubts about who was responsible, he told the station.
"It kinda came together; it was like an 'aha' moment," Lappako said.
In court this week, relatives struggled to come to terms with the idea that the person who took their loved one's life was also a member of their family.
Relatives described James Marshall as a generous, loving father, according to the News-Press. In his final months, he lived in fear of his troubled son, they said, but he chose to live in danger instead of casting his troubled son onto the streets.
"There is no justice for me," said Jordan Marshall, Matthew's brother, according to the Daily News. "I loved my father, James Richard Marshall. I wish Matt a peaceful life."
"I will not hate you, Matt," one of James Marshall's friends said.
But, the friend added: "I just want you to know I'd give anything to hug your father."