“The rule is, and it is nothing more than a rule of practice, that when the guardian becomes the aggressor, the fabric of society frays,” Judge Hamidu Mwanga opened his judgment of a case that involved seven police officers, who were before him facing a charge of murder against Musa Hamis Hamis, a businessman whose murder in 2022 shocked the nation.
“The foregoing statement accurately represents the factual predicate for the judgment I am about to deliver shortly,” Judge Mwanga continued. “The case presents a stark and troublesome paradox: that police officers who sworn to uphold the laws and safeguard the citizens’ lives stand accused of one of the most heinous crimes, which profoundly may lead to breach of the sacred trust reposed in them, whose very presence is meant to be a bulwark against fear, not its source.”
“The court is keenly aware of the profound impact these allegations have on the collective sense of security,” he added. “Today, this court is tasked with the solemn duty of dissecting these grave allegations and delivering justice where it has been so grievously undermined.”
The following is the story leading up to the murder of the businessman and the police’s attempts to cover it up, as extracted from the judgment, which was delivered on June 23, 2025, at Mtwara.
Musa Hamis Hamis was a businessman dealing in minerals, cash crops, and clothing, operating between Dar es Salaam and Nachingwea district, Lindi region. In October 2021, he visited his parents in Luponda-Nachingwea, intending to renovate their house. He informed them he had foreign currency he wished to exchange and subsequently travelled to Mtwara with his associate, Said Makala, staying at Sadna Lodge.
On October 20, 2021, ASP Nicholaus Stanslaus Kisinza received intelligence about two individuals with extraordinary spending habits at Sadina Lodge. Suspecting them of being motorcycle thieves, Kisinza directed Intel/Coplo Salim Juma Mbalu, the seventh accused, to verify the information. Mbalu, accompanied by Shirazi Ally Mkupa, conducted surveillance, confirmed the individuals’ stay at Sadina Lodge, and reported back to Kisinza. Kisinza then instructed them to relay the information to SP Gilbert Sostenes Kalanje, the OCCID, and ASP Charles Maurice Onyango, the OCS of Mtwara Police Station.
Arrest
Following this, Onyango and Kisinza directed A/INSP Marco Mbuta Chigingozi to arrest the two individuals and conduct a search and seizure. Chigingozi assembled a team including himself, Shirazi Ally Mkupa, Intel/Coplo Salim Juma Mbalu, the late Assistant Inspector Grayson Gatian Mahembe, and Assistant Inspector Shadhili Simai Makame.
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Upon arriving at Sadina Lodge, Chigingozi’s team found Musa Hamis Hamis in Room No. 6 and arrested him. A search yielded Sh2,300,000 in cash. Hamis was then taken to Mtwara Central Police Station, detained, and assigned case IR No. MTW/RB/1330/2020, entered in detention register entry No. 271.
Further investigations were deemed necessary, and on October 21, 2021, ASP Charles Maurice Onyango instructed Chigingozi, Mkupa, and Mbalu to accompany Hamis to his residence in Luponda village for additional search and seizure. Onyango issued movement order No. 96774 to facilitate the team’s travel outside the Mtwara region.
At Hamis’s home, Chigingozi conducted a search in the presence of Hamis’s mother, Hawa Bakari Ally. Other police officers from Nachingwea Police Station provided security. During this search, US$13,558, one solar panel, one solar battery, and one inverter charger were seized from Hamis’s residence.
Additionally, Sh1,050,000 was seized from the home of Saidi Ahmadi, a friend of Hamis. One solar panel was left at Nachingwea Police Station due to transport limitations. The remaining seized properties, along with Hamis, were transported back to Mtwara Central Police Station. These properties were reportedly handed over to SP Gilbert Sostenes Kalanje and ASP Charles Maurice Onyango, who are believed to have unlawfully shared them with ASP Nicholaus Stanslaus Kisinza, A/INSP Marco Mbuta Chigingozi, Shirazi Ally Mkupa, and Intel/Coplo Salim Juma Mbalu.
Release and complaints
On October 24, 2021, ASP Charles Maurice Onyango ordered G. 4011 CPL Ikangilo to release Musa Hamis Hamis on bail without sureties. After his release, Onyango gave Hamis Sh130,000 for bus fare and warned him against attempting to reclaim his properties from police custody. Hamis, left with no alternative, returned to his home in Luponda village.
Back in his village, Hamis complained to his family and friends about the police illegally dispossessing him of his properties. He also raised these concerns with various government officials in Nachingwea district, who then channelled his complaints to the National Prosecution Services in Lindi. The Lindi office subsequently contacted the Regional Police Officer in Mtwara for action.
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A/INSP Marco Mbuta Chigingozi became aware of Hamis’s complaints and informed SP Gilbert Sostenes Kalanje, to whom the seized properties had been handed. Kalanje then directed Chigingozi to summon Musa Hamis Hamis to Mtwara Central Police Station to meet Kalanje in his office.
On January 2, 2022, Chigingozi notified Hamis via phone to report to Mtwara Central Police Station. Hamis, feeling uneasy, shared this with his mother, Hawa Bakari Ally, who advised him not to go alone and to notify government authorities. She urged him to contact his uncle, Salum Abdallah Ng’ombo, to accompany him.
Acting on his mother’s advice, Hamis lodged his complaints with the National Prosecutions Service office in Lindi, where he received a letter from the Regional Prosecutions Officer (RPO) referring his complaints to the Mtwara region office.
On January 4, 2022, Hamis, accompanied by his uncle Salum Abdallah Ng’ombo, visited the Mtwara office, where his complaints were received. On January 5, 2022, Hamis received a letter from the Mtwara office confirming that his complaints were being addressed.
Also on January 5, 2022, responding to Chigingozi’s call, Hamis and his uncle went to Mtwara Central Police Station. Hamis informed Chigingozi of their arrival via phone. Chigingozi then instructed the late A/Insp Grayson Gatian Mahembe, who was present, to handle Hamis and take him to SP Gilbert Sostenes Kalanje’s office. These directions were followed.
Interrogation and disappearance
While in SP Gilbert Sostenes Kalanje’s office, Musa Hamis Hamis was interrogated and then locked in a store, awaiting further instructions. Meanwhile, Hamis’s uncle waited for him to emerge from the police station, but Kalanje soon ordered the uncle to leave. The uncle left but tried to call Hamis, receiving no answer. Later, he received a text message from Hamis that read, “waliniachia” (they released me), “tukutane nyumbani” (let’s meet at home). After this, Hamis’s phone became unreachable.
On the same day, SP Gilbert Sostenes Kalanje sought the assistance of Inspector John Yesse Msuya, the In-charge of Mtwara Central Police Dispensary. Kalanje asked Msuya to help eliminate Hamis by injecting him with poison, claiming Hamis was not cooperating in revealing his criminal syndicate involved in motorbike theft. Msuya denied engaging in such unprofessional conduct. Instead, he advised that he could inject Hamis with “Ketamine” to induce a state of cognitive unconsciousness, hoping Hamis would then divulge information about his criminal activities and co-suspects.
Content with Msuya’s advice, SP Gilbert Sostenes Kalanje, ASP Charles Maurice Onyango, and the late A/INSP Grayson Gatian Mahembe removed Musa Hamis Hamis from Kalanje’s office and took him in Kalanje’s motor vehicle. They drove to the Mtwara Police Dispensary to pick up Inspector John Yesse Msuya, then proceeded to Mitengo Police Station.
At Mitengo Police Station, Kalanje and Msuya, who were in the front seat, exited the car. Onyango and Mahembe, along with Hamis, also disembarked and all went inside Mitengo Police Station. They convened in an office-like store that Kalanje had previously requested for interrogating Hamis. Police guards at Mitengo Police Station were instructed not to interfere.
Inside the room, SP Gilbert Sostenes Kalanje told Inspector John Yesse Msuya to inject Musa Hamis Hamis. Msuya heartlessly directed Hamis to lie down and injected him as advised. As Hamis began to lose consciousness, Kalanje interrupted Msuya, stating the process was taking too long. Kalanje then took a cloth and blocked Hamis’s nose and mouth, suffocating him.
This occurred under the watchful eyes of ASP Charles Maurice Onyango and Grayson Mahembe. According to Msuya, he was shocked by this turn of events, as it was not what they had agreed upon, and he left the room.
Afterwards, SP Gilbert Sostenes Kalanje, ASP Charles Maurice Onyango, and the late Assistant/Inspector Greyson remained in the room with Hamis. Approximately 45 minutes later, they emerged and joined Msuya, and all left Mitengo Police Station together in their car. Hamis’s body was left in the room, locked inside with a padlock.
Disposal and recovery
During the night, the late A/INSP Grayson Gatian Mahembe was seen retrieving a stretcher from Mtwara Central Police Station and loading it into a Toyota Land Cruiser (Reg. No. PT 1918), where he met another police officer. SP Gilbert Sostenes Kalanje was driving the vehicle, with ASP Charles Maurice Onyango in the passenger seat.
Kalanje drove to Mitengo Police Station, where Kalanje, Onyango, Mahembe, and the other officer disembarked with the stretcher and went to the room where Hamis’s body was left. Kalanje informed the junior police officers on guard, including Sgt. Jagadi (PW5), that they had come to pick up a sick person.
They placed Hamis’s body on the stretcher and loaded it into the back of the motor vehicle. They then left. The court found that Kalanje drove the vehicle from Mitengo Police Station to the Hiari village forest area within Mtwara district, where they dropped Hamis’s body in the bushes and returned to Mtwara Central Police Station.
On January 7, 2022, Hamis’s mother, Hawa Bakari Ally, and PW2 began complaining about his disappearance, as he was last seen at Mtwara Central Police Station. They reported their concerns to the RCO of Mtwara, ASP Yustino John Mgonja, who promised to investigate.
Confessions
An investigation into Hamis’s whereabouts commenced. Inspector John Yesse Msuya broke his silence, revealing the entire incident that occurred on January 5, 2022, and implicating A/Insp. Greyson. On January 21, 2022, after interrogation, the late A/INSP Grayson Gatian Mahembe also provided a full account of how Hamis was murdered and identified his accomplices.
He further led the police to where Hamis’s body was dumped in the Hiari Forest area. Following this revelation, Mahembe was detained at the Police Station. That same night, news spread that he had hanged himself while in custody.
At the crime scene in the forest, police recovered ten human bone remains. A sketch map was drawn, and photographs were taken. The bones were sent to the Government Laboratories Authority for DNA profiling. On January 24, 2022, Hamis’s mother, Hawa Bakari Ally, provided DNA samples for comparison.
The DNA profiling test confirmed that the bones found in the bush were related to and matched Hawa Bakari Ally, the mother of the deceased. Following this thorough investigation, the accused persons were arraigned in court and charged.
All accused pleaded not guilty, prompting the prosecution to present twenty-eight (28) witnesses and sixteen (16) exhibits. The defence presented their case and tendered three exhibits. The Republic was represented by various legal officers, including Matenusi Marandu, Paschal Marungu, Joseph Maugo, Chivanenda Luwogo, Kassim Nasiri, Ignas Mwinuka, Farida Kiobya, Jaggad Jilala, and Karangi Joels. The accused persons were represented by Mr. Majura Magafu, Fredrick Ododa, Nehemia Nkoko, Allex Msalenge, Felister Awasi, Steven Lekei, and Emmanuel Ngongi.
After the closure of the defence case, both parties expressed their desire to present closing submissions, which were granted. The court has carefully reviewed the evidence presented by both parties.
‘Unconscionable violence’
In delivering the judgment, Judge H.R. Mwanga reflected on the profound implications of police officers committing such crimes, citing the words of Sarkar’s Law of Evidence: “Rarely in cases of police torture or custodial death, there is any direct ocular evidence of the complicity of the police personnel who alone can only explain the circumstances in which a person in their custody had died. Bound as they are by the ties of brotherhood, it is not unknown that the police personnel prefer to remain silent and more often than not even pervert the truth to save their colleagues.”
The judge emphasized the need for courts to deal with such cases “in a realistic manner and with the sensitivity which they deserve, otherwise the common man may tend to gradually lose faith in the efficacy of the system of judiciary itself, which, if it happens, will be a sad day, for anyone to reckon with.”
Judge Mwanga stated that the court was convinced the motive behind Hamis’s death was to cover up the accused’s act of robbing his property. “Such unconscionable violence erodes public trust and undermines the very principle of justice,” the judge declared.
“Indeed, the integrity of any society hinges on the unwavering principle that no one, regardless of their position or power, stands above the law,” he added. “It is not expected that those who swore to uphold the law and safeguard the lives of citizens would commit its most heinous violation. This is a betrayal of trust and a disregard for the importance of justice. The brutal killing of Musa Hamis Hamis is indeed an outrageous abuse of power. It is a tragic and unacceptable practice within a civilised society. It is intolerable and should not be condoned.”
Conviction and sentencing
After careful consideration of all facts and analysis, Judge Mwanga concluded that SP Gilbert Sostenes Kalanje and ASP Charles Maurice Onyango killed Musa Hamis Hamis with malice aforethought. Consequently, the court found Kalanje and Onyango guilty of murder, contrary to sections 196 and 197 of the Penal Code [Cap. 16 R.E. 2019], now R.E. 2022, and convicted them accordingly.
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Conversely, ASP Nicholaus Stanslaus Kisinza, A/INSP Marco Mbuta Chigingozi, Inspector John Yesse Msuya, Shirazi Ally Mkupa, and Intel/Coplo Salim Juma Mbalu were found not guilty, as the prosecution failed to prove their guilt beyond a reasonable doubt. They were acquitted and set free.
In sentencing, Judge Mwanga stated: “As this is a murder case, my hands are tied by my oath of office to uphold the Constitution and to respect the laws of the land. In our law on criminal offences, there is only one penalty for the offence of murder, and that is death by hanging.”
Therefore, Gilbert Sostenes Kalanje and Charles Maurice Onyango were sentenced to suffer death by hanging until they die. They were also instructed that they can appeal both the conviction and sentence.
The judgment was delivered at Mtwara on June 23, 2025.
