When Ruby Mashao looked at his son, David, sitting in the dock at the high court in Johannesburg, he could not see the church-going boy he had raised.

Last week, Mashao’s extended family listened as the 29-year-old confessed to how he had joined a satanic church, tried to recruit his siblings, Barbara, 22 and Sechaba, 28, and, when they refused, decapitated them with a kitchen knife. The two murders happened six years apart.

Mashao pleaded guilty to two murder charges after reaching a plea agreement with the state, and was sentenced to two life terms.

His lawyer, Lebohang Mosoang, had tried to argue his client had been possessed on the days he had beheaded his siblings, and that he had since “turned his back on his so-called god, Satan”.  He asked judge Frans van der Westhuizen to consider a lesser sentence than life in prison.

“It wasn’t my son there in court,” Ruby said earlier, sitting on the floral bedspread in his son’s room in their Roodepoort home. The walls in the small bedroom have been repainted to cover up a series of satanic and Illuminati symbols Mashao had scrawled across them.

Mashao managed to evade suspicion after his brother’s headless body was found near the Roodepoort railway station in 2012. It was initially thought Sechaba had been hit by a train, but train officials said no one had been hit that day.

The inquest was ultimately inconclusive and the Roodepoort magistrate’s court ruled that though it was probably a murder, there wasn’t enough evidence to name a suspect.

Last year, Ruby was hospitalised after suffering a stroke, leaving Mashao and Barbara at home with their uncle, Miguel Mashao.

Ruby told the Sunday Times that Mashao and Barbie, as she was affectionately known, would both attend services at the local Jehovah’s Witnesses church, and lived together happily at the family home.

He would later write in his confession statement: ‘My sister and I were at home when I decided to attack her, stab her and cut off her head with a knife’

But by 2018, the relationship had soured, with Mashao openly telling his uncle and sister he was part of the “Church of Satan”.

On August 16, Miguel had left for work, and Mashao tried to convince Barbara to become a satanist.

He would later write in his confession statement: “My sister and I were at home when I decided to attack her, stab her and cut off her head with a knife.”

When Miguel returned home, he found Barbara’s body in the kitchen, her head lying in her own arms.

Police officers summoned to the scene found the walls in the house had been marked with various symbols, including a swastika and numbers.

Above Mashao’s bedroom mirror was his sister’s name, “Barbie”, scrawled beneath an Illuminati-style pyramid with the “Eye of Providence” in the centre.

Mashao was arrested at a nearby taxi rank.

In court, Mosoang read out Mashao’s plea statement: “My deceased sister and my deceased brother were against my religious Satanism beliefs and I then planned to kill them in a sacrifice to my Satanic religion.”

State prosecutor, Advocate Deon van Wyk, in aggravation of sentence, described the killings as among the “most gruesome imaginable”.

Van der Westhuizen sentenced Machao to two life sentences, calling him “a very dangerous person”.

But for Ruby, who now lives alone in the family home where his daughter was killed, the sentence provided little comfort.

“I was devastated. I am still devastated,” he said.