The trio was arraigned on Monday as the Directorate of Criminal Investigations (DCI) told the court that they played a specific role in the killing.

In his ruling,  Magistrate Paul Mutai noted that the safety of the three suspects can't be guaranteed if released at this stage. 

"I note that one of the suspects is a serving police officer and if the respondents are released on bond there's a likelihood that they will interfere with investigations," he ruled.

In an affidavit, DCI Homicide Investigations Bureau officer Corporal Romana Odour says preliminary investigations have already established the alleged roles of the suspects.

“Preliminary investigations have established that the 1st respondent, Kimoi, is the one who fired the fatal shot,” Odour stated. 

Investigators allege that Njoroge, the second respondent, was driving a black Toyota Prado registration number KDH 600A, which allegedly blocked the Uber Toyota Passo registration KDJ 609D in which Dr. Mutiso was aboard.

The third suspect, Kinuthia, is alleged to have used motorcycle registration number KMGZ 980D to transport Kimoi to and from the scene.

The affidavit states that the three suspects were arrested on August 7, 2026, during what the DCI describes as an “intelligence-led operation” and were placed in custody at Ruaraka, Pangani, and Gigiri police stations, respectively. 

Dr. Mutiso, a former Director of the African Institute of Mental and Brain Health, was fatally shot on July 29, 2026, in Upper Hill, Kilimani Sub-County, Nairobi, while inside a motor vehicle registration number KDJ 609D.

The incident was reported at Kibra Police Station under OB Number 35 of July 29, 2026, before the Homicide Investigations Bureau at DCI Headquarters took over the investigation. 

Investigators told the court that they recovered two spent cartridges and two bullet fragments from the scene and submitted them for forensic examination.

A Mini Jericho pistol, serial number 47302127, was subsequently recovered and examined.

According to the DCI, “the preliminary ballistic opinion links the recovered cartridge cases and bullet head to that firearm.”

Investigators further say the firearm was issued to a senior police officer who is at large. 

The DCI has also identified a land dispute involving Dr. Mutiso as a possible motive for the killing.

Investigators say the deceased was involved in a dispute over L.R. Number 1504/13, which is the subject of a case before the Machakos court.

The application states that the land dispute might be one of the motives for killing the deceased.

Investigators also say Dr. Mutiso had previously reported that someone had attempted to kill her and that she had been followed before the fatal shooting. 

The DCI says that on July 7, 2026, Dr. Mutiso reported being confronted by two armed men riding a motorcycle near Junction Mall along Ngong Road in Nairobi.

According to the application, the men pointed a gun at her but she managed to escape and later reported the incident at Kilimani Police Station.

Investigators allege that Kimoi was one of the armed men involved in that earlier incident. 

The DCI has identified Dr. Mutiso's husband as a crucial witness in the investigation.

However, investigators say he is yet to record a comprehensive statement due to the traumatic circumstances surrounding his wife's death.

According to the affidavit, his evidence is key to probing previous threats against Dr Mutiso and identifying the suspects involved.

The DCI says releasing the suspects could expose the husband and other witnesses to interference or intimidation. 

The outstanding investigations include recovering other firearms suspected to have been used in the murder, forensic analysis of CCTV footage and call-data records, examination of the detained vehicles and motorcycle, recording of outstanding witness statements and establishing the respective roles of the suspects.

The State says continued detention is necessary because some suspects who remain at large could collude with those already arrested.

“Continued detention is therefore necessary to preserve the integrity of the investigations,” Corporal Odour noted. 

The DCI says critical investigations are yet to be completed while more accomplices remain at large. Citizen Digital