Benjamin Nnayerugo, also known as Killaboi, told a Lagos State High Court that he accidentally stabbed his girlfriend, Augusta Onuwaghagbe, while trying to take a steak knife from her during a fight at his home.
He said Augusta, a 21-year-old student at Lead City University in Ibadan, threatened to stab him after he insulted her mother during an argument about messages he found on her phone.
Nnayerugo shared this account on Thursday as he continued his testimony before Justice Ibironke Harrison at the Lagos State High Court at the J.I.C. Taylor Courthouse in Igbosere.
He is on trial for two charges related to the alleged murder of Augusta, an online influencer whose body was found in his apartment at Oral Estate, Ajah, Lagos, on July 15, 2023.
With his lawyer Marcel Oru (SAN) guiding him, the defendant described the events that led to the incident. He said it started with a disagreement about their six-year relationship and claimed that she was planning to meet another man for commercial sex.
On Wednesday, Nnayerugo told the court he learned of the alleged arrangement after looking through Augusta’s phone. He then told her he wanted to end their relationship.
He said he called Augusta’s mother to explain his decision, but hung up when she questioned him about looking through her daughter’s phone.
On Thursday, the defendant continued his testimony. He said he spoke with Augusta for a long time on the night of July 11 and into the next morning. During the call, she told him she was no longer interested in the relationship.
He said he felt used after recalling the money and gifts he had spent on her over the years, including a trip to Seychelles in 2022, her university fees in January 2023 and about N20 million on diamonds, an iPhone, AirPods and a private lounge for her birthday celebration in February 2023.
“I started listing out all I had done for her since she said she had checked out of the relationship,” he told the court.
He said he eventually agreed to meet Augusta at his residence on July 12 after receiving a message from her mother concerning the man she was allegedly negotiating to meet.
According to him, the message suggested Augusta had known the man before she began dating him, which he took as a sign that her mother supported her decision to leave him.
Nnayerugo told the court that Augusta later joined him in his bedroom, where they smoked marijuana together before eating and sleeping separately.
He said that the following morning, he became determined to access her phone after an earlier attempt to read her WhatsApp messages had failed because she had changed her password.
The defendant said he pretended to have a cough and asked Augusta to get him water from the refrigerator before snatching her phone as she turned away.
He alleged that she rushed at him, demanding that he return the device, while he used one hand to check her messages and the other to keep her away.
According to him, he discovered conversations between Augusta and her mother which he interpreted as showing that her mother had advised her on what to tell him about the alleged cheating and had encouraged her to leave the relationship.
He said he became angry and called Augusta’s mother a fake pastor, prompting an angry reaction from Augusta.
Nnayerugo alleged that she picked up a knife from a table and threatened to stab him if he did not return her phone.
He claimed she stabbed him in both hands but that he continued to hold on to the device because he wanted her to return it alongside other gifts he had bought for her.
He further alleged that Augusta threatened to stab him in the chest and kill him for insulting her mother, prompting him to attempt to take the knife from her.
Describing the struggle, the defendant said they wrestled over the knife for about 10 minutes, with Augusta holding the handle while he held the blade.
“We dragged the knife for about 10 minutes; she was holding on to the handle while I held the tip,” he said.
He told the court that he eventually managed to grab the handle but realised during the struggle that Augusta had been stabbed in the stomach.
“At that point she was hit and fell down. It was then my eyes cleared. Blood came out from her stomach and her mouth,” he said.
The defendant said he tried to save her by removing the knife from her stomach and using a towel to cover the wound in an attempt to stop the bleeding.
“I told her not to die and that I won’t break up with her again,” he added.
Nnayerugo was arraigned in November 2025 and pleaded not guilty to the two-count charge.
His trial began after his extradition to Nigeria, following about two years on the run. He was eventually arrested in Doha, Qatar.
The court adjourned further hearing until December 7 and 8, 2026.