Daughter, 15, told uncle how she wanted to kill her mom

“Some day I'm going to kill my mother.”

These words still haunt Donald Brown, the uncle of a woman who has confessed to murdering her mother, father, eight-months-pregnant sister, and three-year-old brother.

The chilling say was made to Brown by Onthatile Sebati three months before the 2016 murders. Onthatile was just 15 years old at the time and upset after a quarrel with her mother.

Onthatile is charged, along with her cousins Kagiso and Tumelo Mokone, with four counts of murder, robbery with aggravating circumstances, possession of a firearm, possession of ammunition, and theft. On Friday, judgment was reserved in the Pretoria high court.

This week, family members and neighbours painted a picture of a stubborn teenager who constantly clashed with her mother.

But how did typical teenage rebellion turn into cold-blooded mass murder?

The North West family, who lived in a village outside Brits, seemed to be a normal, close-knit, middle-class family.

Dad Solomon Lucky Sebati, 41, was a police officer, pastor and businessman who owned a funeral parlour. Mom Mmatshepo, 40, was a nurse at an old-age home who “loved people”.

Sister Tshegofatso was a “darling and would not harm anybody” who was excited about the imminent birth of her child, while brother Quinton, 3, loved to play soccer.

All of them were shot dead with Solomon's service pistol. 

Yet, despite Onthatile's ominous words to her uncle months before their deaths, most friends and family members never saw it coming.

“About three months before the murders, Onthatile came to me. She was crying and angry. When I asked her what the matter was, she said: ‘My mother. Always my mother. Some day I am going to kill my mother,” Brown, 63, told the Sunday Times.

“Onthatile was a very stubborn and rebellious child who didn’t like taking orders, especially from her mother.”

He believes this rebellious spirit and a “lust for money” are the reasons for the family murder.

“She is saying she was mistreated, but that is not true. She had a lot of conflict with her mother about discipline. I was asked on several occasions to intervene.”

In her confession, Onthatile said her family had been “abusive”, and that she had always been “assaulted and insulted”.

“We decided on a plan to kill them all,” her confession statement said.

“First we decided to use sleeping tablets, which I poured into their food that I prepared on December 5 2016. Then, on December 6, during the day — before the murder — I [told my cousins] Tumelo and Kagiso through WhatsApp that they must come collect the firearm belonging to my father,” she said.

She is saying she was mistreated, but that is not true. She had a lot of conflict with her mother about discipline 

—  Donald Brown, Onthatile Sebati's uncle

The men came, took the firearm, and then returned at about 11pm, she said. 

“I gave Tumelo the car key to the Chrysler to reverse it, and Kagiso and [I] went into the house. I showed him where my father [was], then he shot him, and where my mother [was], and my sister who was pregnant came out to see what was happening. Kagiso also shot them dead,” she said.

“He also shot my little [brother] — the little one.”

Onthatile said she told Kagiso to also shoot her. He shot her in her right thigh.

According to the confession, after the two drove away, Onthatile told neighbours two suspects had shot her family.

It is alleged Onthatile paid her cousins R100,000 to help her commit the murders.

Before the Mokones were arrested in 2021, two other men stood trial for the killings. But after revealing they had been assaulted into confessing and told what to say, they were acquitted.

Brown, who worked for the Rosslyn fire department at the time of the killings, said the entire family had initially felt sorry for Onthatile after the murders.

“During one of the earlier court appearances [in the initial trial], police had to hold Onthatile back when she wanted to attack [the accused]. My heart broke for her that day.”

Shortly before Onthatile's arrest in 2021, Brown had another worrying conversation with her. 

“She was crying again. I asked her what the matter was, and [she] said: ‘Uncle, I am so sorry. Please forgive me.’ When I asked her what for, she refused to tell me.”

Solomon's niece, Dolly Brown, said she was devastated. 

“I have been hurt to the point where at times I can’t even sleep when I think of Lucky, his wife and the children. If Onthatile [were] to be released, I wouldn’t ever want to be associated with her in life. I'm afraid of her.” 

She says Onthatile’s mother, Mmatshepo, was a loving person.

“She worked as a nurse at an old-age home, and she loved people. Her 19-year-old sister, Tshegofatso, was a darling and would not have harmed anybody. She was heavily pregnant — almost nine months.”

Three-year-old Quentin was also killed in the attack.

“I imagine the terror of a young child. That pain of being helpless makes me feel pain just like a child,” she said.

George Motaung, 38, worked for Solomon in his Mmakau mortuary and was close to the family.

“They were like parents to me, and Onthatile was like a little sister. But when I heard the news, I was not surprised. I always knew she was capable [of that],” Motaung said on Friday. 

He said Onthatile had sold a lot of her parents’ belongings after the murders.

“She sold two cars, furniture, the washing machine, the fridge and a lot of other household [items], as well as mortuary equipment.”

However, he doesn’t believe money was the motive for the killings. 

“She liked the money, but this was all about control. Onthatile hated being controlled and wanted her freedom.”   

He is heartbroken about the deaths of the family.

“Little Quinton loved to kick a soccer ball about in the yard, and Tshegofatso was a very good girl.”

When the Sunday Times visited the family home this week, its unkempt garden and abandoned Chrysler in the yard stood in stark contrast to the neat and well-tended gardens lining the street. 

A neighbour said Onthatile had clashed with her mother about household chores and discipline.

“They were often fighting because she did not like being told what to do. Some weeks the school called her parents as many as three times.”

On the night of the killings, the neighbour, who did not want to be named, had just got into bed when she heard a gunshot, “then another and another, until seven in total rang out”.

She was too scared to venture out of her house. 

“Then we heard the Sebatis' car start. Their gate was locked, and the car crashed through the locked gate to exit the property.

“Then a screaming Onthatile came running about the house. She ran to another house and sounded the alarm. More villagers came running.”

Onthatile attended Tsogo Secondary School, about 2km away from her home. 

A teacher at the school, who asked to remain anonymous, confirmed her problematic disciplinary record.

“Her parents were frequently called to the school because of her behaviour. There were a lot of problems with discipline. I was not surprised when I heard what had happened,” the teacher said.

Advocate Nelson Khoza, who represents Onthatile Sebati, said: “Judgment was reserved [in the matter] until [Onthatile's] next appearance on January 24.”