Mother, son arrested over murder of mental health researcher Dr Victoria Mutiso in Nairobi
Mental health researcher Dr Victoria Mutiso
Two suspects were Thursday arrested for grilling in connection with the fatal shooting of clinical psychologist and mental health researcher Dr Victoria Nthunya Mutiso in Nairobi.
The persons of interest are a mother and her son, police revealed.
They are believed to know how and why Dr Mutiso was killed.
This is after it emerged the murder could be linked to the family dispute over property.
Dr Mutiso was shot dead by gunmen in a suspected targeted attack in Nairobi on Wednesday morning.
Police said Dr Mutiso was ambushed near Kenyatta National Hospital while travelling in a taxi to her family owned facility and office.
She had arrived at the entrance of the offices.
According to police and witnesses, Dr. Mutiso had requested an Uber ride from Tanga Heights Apartments on Bamboo Lane off Riara Road to the Africa Institute of Mental and Brain Health at Mawensi Gardens off Matumbato Road in Upper Hill.
The Uber driver told police that upon reaching the Mawensi area, he encountered a black Toyota Prado that had partially blocked the road, forcing him to slow down.
Moments later, he heard a loud gunshot from the rear left side of the vehicle where Dr. Mutiso was seated.
He reportedly saw a man armed with a pistol firing at his passenger before speeding away from the scene while avoiding the Prado.
According to investigators, a four-wheel-drive vehicle blocked the taxi before two gunmen riding on a motorcycle opened fire at close range.
She sustained critical gunshot wounds and was rushed to hospital, where she was pronounced dead.
Preliminary investigations indicate the assailants had trailed Dr Mutiso from her home near the Junction area in Nairobi’s Kilimani neighbourhood before carrying out the attack.
Police described the killing as a targeted murder, saying detectives were pursuing crucial leads.
Crime scene investigators recovered a spent cartridge from the scene, which has been forwarded for ballistic examination as part of the ongoing investigation.
Dr Mutiso had previously reported threats to her life at Kilimani Police Station after armed men riding on a motorcycle allegedly pointed a gun at her while she was caught in traffic. Investigations into that incident were still ongoing.
Detectives arrested a woman and her son on Thursday over the shooting.
They were under interrogation to provide more on the incident, officials said.
The shooting is said to be linked to the Nairobi lawyer Mathew Kyalo Mbobu along Magadi Road in Nairobi on September 9, 2025 evening at about 5.30 pm.
Police said they believe the killing of Dr Mutiso will open up more on the murder of Mbobu.
No arrest has been made over the murder of Mbobu.
Detectives are also examining reports of a family dispute over property, which they believe could be among the possible motives behind the killing.
Dr Mutiso was second wife to Prof David Ndetei, a prominent Kenyan psychiatrist and academic, serving as Professor of Psychiatry at the University of Nairobi since 1995.
A team visited her home as part of the probe and talked to her family. She was a mother of two.
She planned to solemnize her marriage in a week.
Dr Mutiso was a respected figure in Kenya’s mental health sector and served as Head of Research at the Africa Mental Health Research and Training Foundation (AMHRTF). She specialized in youth mental health, substance abuse and the integration of mental health services into community healthcare.
Her work focused on child and adolescent mental health, including the development of culturally appropriate tools and interventions aimed at promoting mental well-being and preventing the onset of severe mental illness among young people, particularly in underserved urban informal settlements and rural communities.
Throughout her career, Dr Mutiso led and co-investigated numerous research projects on mental illness, neurological disorders and substance abuse in collaboration with local and international partners.
She also co-led the NIHR Global Health Research Group project “HOPE,” which focused on homelessness and severe mental illness in Africa, and authored numerous publications that significantly contributed to public mental health research in Kenya.