Prosecutors have alleged in a High Court affidavit that suspects charged with murdering clinical psychologist Dr. Victoria Nthunya Mutiso plotted to poison witnesses cooperating with the investigation, after an associate was allegedly caught delivering poisoned food to one such witness at a Nairobi police station.

The affidavit, filed to oppose bail for Rose Mbithe Mulwa, her children Chris and Angela Mulwa, and two others, says the group is accused of orchestrating the July 29 killing of Dr. Mutiso over a long-running dispute involving a 20-acre parcel of land in Mlolongo tied to the deceased, her husband and the first three accused. Prosecutors allege the group conducted surveillance on Dr. Mutiso, gathered personal information about her and her family, and coordinated communications and logistics for roughly four months before the killing. According to the affidavit, Dr. Mutiso had reported being confronted by two armed people on a motorcycle near Junction Mall along Ngong Road on July 7, weeks before she was intercepted while travelling in an Uber and fatally shot.

Investigators say they received intelligence on Aug. 20 about an alleged plot to harm suspects who had agreed to cooperate with the probe. Two days later, a fifth accused, identified as Maritim Kimutai, was arrested at Pangani Police Station while allegedly visiting one of the cooperating suspects and carrying poisoned food intended for that person. Detectives say information recovered from Kimutai's phone helped them trace and arrest three additional suspects who had fled to Uganda, including Police Constable Collins Bett Kilangat, who was named earlier in the case alongside another officer, Elijah Kibelion Kimoi, accused by the Directorate of Criminal Investigations (DCI) of firing the fatal shot.

Prosecutors argue that releasing any of the accused on bail would risk witness interference, destruction of evidence, collusion among suspects and flight, and say the investigation remains ongoing, with several alleged accomplices, including some senior police officers, still at large.