When former Kenya Air Force Major Peter Mwaura Mugure denied fathering two children born to Joyce Syombua, the dispute was initially confined to the Children's Court.
A DNA test ordered by the Milimani Children's Court settled the matter. The results confirmed that Mwaura was the biological father of the two minors, Shanice (10) and Prince (5). The court also compelled him to provide financial maintenance for the children.
Following the ruling, Mwaura returned to his duty station at Laikipia Air Base in Nanyuki. It was there that he meticulously planned the elimination of Joyce and the two children in what the High Court would later describe as a premeditated triple murder.
Justice Martin Muya found him guilty of killing Joyce Syombua and their two children on October 26, 2019 before disposing of their bodies in a shallow grave outside the military installation.
Former KDF Major Peter Mugure at Milimani High Court on July 14, 2026.
Photo credit: Billy Ogada | Nation Media Group
The prosecution tabled evidence showing that Mwaura invited Joyce and the children to Laikipia Air Base under the guise of a family visit.
Corporal James Mwaniki, one of the investigators, produced financial records showing that on October 22 and October 24, 2019, Mwaura sent Joyce money to facilitate her journey from Nairobi to Nanyuki with the children.
Further, mobile phone records later placed Joyce and the children at the military base after they arrived.
Evidence before court showed that on the morning of October 26, Mwaura took the two children away from the house, ostensibly to show them around the air base. Joyce remained behind.
The children never returned alive. Later that evening, prosecutors said Mwaura killed Joyce. Post-mortem examinations conducted by Chief Government Pathologist Dr Johnson Oduor revealed that Joyce died from blunt force trauma to the head, while both children were strangled.
For weeks after the family disappeared, investigators had little idea what had happened inside the military installation.
To show how Mwaura planned the killing, the prosecution pierced together evidence showing that he visited the burial site three days before the killings and arranged for a shallow grave to be dug, demonstrating premeditation and a deliberate plan to eliminate his family.
The key witness, Collins Pamba, then a 21-year-old sanitary orderly at the officers' mess, gave investigators a detailed confession describing how he unknowingly became part of the cover-up.
Pamba said he had travelled to Nairobi on October 25 to visit his girlfriend before returning to Nanyuki the following day. During the journey back, he received several phone calls from Mwaura, who repeatedly told him he had a job for him at the air base.
That night, after several missed calls, Pamba finally met the officer.
Instead of assigning him routine work, Mwaura allegedly led him into staff quarters.
Inside a bathroom, Pamba found the bodies of two children wrapped in transparent gunny bags and tied with ropes. In an adjoining room lay the body of an adult woman.
According to his statement, Mwaura warned him that if he disclosed what he had seen he would be killed. He then allegedly promised to help him secure recruitment into the KDF if he cooperated.
The two loaded the bodies into the boot of Mwaura's Subaru Impreza before driving to a dumpsite near Thingitu Estate.
There, prosecutors said, Mwaura had already prepared a shallow grave.
Pamba told investigators they buried the bodies under the cover of darkness before returning to the base shortly before 1am.
The following day, he washed Mwaura's house and vehicle and was paid Sh4,000.
He later handed over photocopies of his academic certificates after Mwaura allegedly promised to secure him military employment.
Collins Pamba, the second suspect in the murder of Joyce Syombua and her two children, when he appeared in court in Nyeri on December 9, 2019.
Photo credit: File | Nation
According to investigators, Mwaura even sent him Sh1,030 through M-Pesa to buy a new spade, instructing him to periodically cover the grave with fresh soil to avoid attracting attention.
Pamba remained silent until November 16, 2019, after military officers and detectives questioned him about the disappearance of Joyce and her children.
Initially charged alongside Mwaura with murder, Pamba later entered into a plea bargain with the Office of the Director of Public Prosecutions. The murder charges against him were withdrawn and substituted with the lesser offence of being an accessory after the fact of murder, allowing him to testify for the prosecution.
Mwaura challenged that agreement in court, arguing that it unfairly strengthened the prosecution's case against him.
High Court judge Maureen Odero rejected that argument, holding that the plea bargain was lawful and did not violate his constitutional rights.
Joyce Syombua (left) and her children, Shanice Maua and Prince Michael. Their bodies were dumped in a shallow grave at a cemetery in Nanyuki.
Photo credit: Pool
“It is my opinion that the above provision makes perfect sense. One cannot claim to be a victim of the very crime which one is charged with having committed. In my view the ODPP was perfectly entitled to consider and to enter into a plea bargain agreement with Collins Pamba notwithstanding the fact that the persons alleged to have been killed were family members of the petitioner,” said the judge.
The court noted that it was quite common for the ODPP to secure plea agreements with one or more accused persons where several persons have been charged with the same offence.
“I find nothing illegal and/or unprocedural in the plea bargain agreement entered into in this matter,” said the court.
Mwaura later attempted to stop his prosecution altogether, arguing that since he was a serving KDF officer, he could only be prosecuted before a Court Martial under the Kenya Defence Forces Act by the Director of Military Prosecutions.
The court ruled that murder is an offence under the Penal Code and that the High Court had jurisdiction to try him despite his military status.
Besides Pamba's testimony, prosecutors relied heavily on forensic and digital evidence.
Chief Inspector Joseph Kolum told the court that phone records showed both Mwaura's and Joyce's phones remained active on October 25 until around 6.16 p.m., when Joyce's phone went silent while still within the air base.
Former KDF Major Peter Mugure in a Nanyuki court on November 18, 2019.
Photo credit: File | Nation Media Group
Cybercrime expert Chief Inspector Peter Kinyua, attached to the Directorate of Criminal Investigations headquarters, extracted data from phones belonging to the victims and several witnesses.
Although investigators recovered messages from the victims' devices and witness phones, they were unable to retrieve messages from Mwaura's handset because they had been deleted.
The recovered SIM card data nevertheless corroborated witness accounts and helped investigators reconstruct the movements of those involved.
Investigators also recovered a spade, a jembe and a pair of black shoes linked to Pamba.
Forensic examination found soil on the exhibits that matched soil samples collected from the shallow grave, placing him at the burial site exactly as he had described.
DNA analysis also confirmed that Shanice and Prince were biological children of both Joyce Syombua and Peter Mwaura Mugure, reinforcing the prosecution's theory that the murders followed the paternity dispute and maintenance orders issued by the Children's Court.
Justice Muya found that the prosecution had proved every ingredient of murder under Sections 203 and 206 of the Penal Code.
The court held that the evidence demonstrated malice aforethought and showed that the killings were carefully planned.
Witness testimony established that Mwaura had visited the burial site three days before the murders and arranged for a shallow grave to be dug, demonstrating clear premeditation.
The judge found the prosecution's evidence cogent, credible and consistent, leaving no reasonable doubt that Mwaura murdered Joyce and the two children before concealing their bodies.
During sentencing, prosecutors Jennifer Kaniu and Pithon Mwangi urged the court to impose the death penalty.
The court instead sentenced Mwaura to life imprisonment on all three counts, with the sentences running concurrently.
He further observed that the country was witnessing increasing cases of femicide and infanticide that demanded stern punishment.
Describing the murders as "barbaric", the judge concluded that a life sentence was appropriate while taking into account the period Mwaura had already spent in custody.
