In September 2023, tragedy struck a quiet home in Kiamumbi estate, Kiambu County.
Henry Nkulu Igweta, 81, a retired Kamiti prisons boss, and his wife, Beatrice Kabutia, 71, a retired teacher, lost their lives within days of each other.
Doctors later confirmed that the couple had been poisoned.
Nearly two years later, their house help, who had been missing has been tracked down and arrested by police.
Today, Daniel Kimathi Kiamba is expected to appear at the Kiambu Law Courts to face two counts of murder.
But even with an arrest, the questions are more than the answers. Why were the couple killed? Who wanted them dead and was the suspect acting alone, or was he a pawn in a larger scheme?
According to investigation documents, the chain of events began on September 28, 2023, when Henry Nkulu suddenly began vomiting.
He was rushed to Aga Khan Hospital and admitted to the High Dependency Unit, where he remained for a week before succumbing on October 5.
Days later, Beatrice, his wife, was found unconscious in her bed. She was rushed to Kenyatta University Referral Hospital, where she was declared dead on arrival.
Autopsy reports confirmed that both had been poisoned: Henry with a combination of Amitraz and Cypermethrin, Beatrice with Amitraz and Carbaryl. Food samples taken from their home contained the same poisons.
The man believed to have prepared those meals? Their house help, Kimathi.
According to the investigators, Kimathi had lived with the couple since 2022, taking care of household chores, including preparing meals.
But on the morning Henry fell ill, Kimathi reportedly vanished.
He left the house around 5 a.m., leaving the ailing man behind. Later that day, when news spread of Henry’s worsening condition, Kimathi switched off his phone.
For nearly two years, officers from the Directorate of Criminal Investigations (DCI) Homicide Department trailed him.
Police say Kimathi frequently changed mobile lines, registering them under different identities. He was never found at his rural home in Meru. That is, until earlier this month.
On the night of August 9, 2025, detectives pounced into the vast Kasarani area in Igembe North, near Meru National Park. Kimathi was allegedly hiding there, staying under the radar.
Sources familiar with the investigation suggest he had drawn attention after attempting to buy a phone through a digital lender, Mkopa. His trail finally caught up with him. He was escorted to Kiambu Police Station and booked, facing two counts of murder.
Professor James Mbaria, an expert in phamarcology and toxicology at the University of Nairobi, paints a grim picture of the chemicals used in the deaths.
“Amitraz depresses the cardiovascular system, it can cause collapse of the heart and lungs within hours if ingested in high doses. Cypermethrin, on the other hand, is a pyrethroid pesticide that affects the nervous system. Signs include convulsions, nervous disturbances, and eventually death,” said Mbaria.
According to Mbaria, the combination of such poisons is particularly lethal.
“If ingested together, one affects the nerves while the other attacks the heart and lungs. Breathing, heartbeat, and nervous control are vital functions, and once they fail simultaneously, death is swift,” he said.
Kennedy Njuguna, a neighbor of the couple, said that the deceased rarely got out of their compound and they were shocked to learn that they had died.
“At first we thought the old man was just sick. Later we heard he had died, then his wife too. It was shocking because losing two people at the same time was not normal. Later on, we were told it was poisoning,” said Njuguna.
To them, the Nkulu's were reserved, peaceful retirees and tthe deaths left them heartbroken.
But even as detectives push forward, the children of the deceased have resisted publicity.
Through their lawyer, they wrote a letter opposing any media coverage of the deaths or the ongoing case.
“Broadcasting or publishing any story concerning the affairs and death of the late Henry and Beatrice Nkulu at this time will negatively influence public opinion and emotions, potentially hindering an impartial and thorough investigation in addition to embarrassing justice,” reads the letter in part.
