A Nairobi court has heard that mobile phone data connected prime suspect Isaiah Murangiri to several sites within the city centre on the day university student Rex Masai was fatally shot during protests.
Safaricom senior manager Zachary Kirogoi Mburu testified before Principal Magistrate Geoffrey Onsarigo that the company had been compelled by two court orders to release call records and location details for phone numbers under investigation between June 18 and 20, 2024.
According to Mburu, a number registered in Murangiri’s name was active on June 20 at 11:20 am at St. Ellis House and later between 3:56 p.m. and 6:21 p.m. at the same location. That evening, the same line connected to a site near Kencom.
“On June 20, 2024, the number under the name of Isaiah Murangiri was active and showed multiple records within the CBD,” Mburu told the court.
He explained that while one of Murangiri’s lines only sent a single SMS and had no other activity during the three days, another of his numbers generated 30 records, mostly linked to Windsor House, Accra Road and Corner House, with usage stretching from early morning to late evening.
The court also heard that a number belonging to Benson Thiru Kamau was picked at KBC Towers from 5:00 p.m. on the same days, while a line under Michael Okello showed no records on June 19.
During earlier cross-examination, Murangiri insisted he had stopped using the number in question a year earlier. But Mburu clarified that Safaricom records still listed him as the registered user at the time of the court order.
“The details presented before the court confirmed that on June 20, 2024, the number was under the name of Isaiah Murangiri, and it was active,” he said.
He further explained that within Nairobi’s CBD, network masts cover about five kilometres, which meant a subscriber did not need to be physically at a site for their signal to be captured. “Murangiri may not have moved, but Kencom still captured his signal,” Mburu testified.
The prosecution argued that the Safaricom records weakened Murangiri’s defence and placed him in the CBD when Rex was killed.
In a separate testimony, ballistic expert Senior Superintendent of Police Alex Mutindi Mwandawiro told the court that he examined a damaged bullet jacket delivered to him by IPOA investigators on July 1, 2024.
The copper fragment, weighing 0.83 grams, was identified as part of a 5.56mm rifle round.
He said the bullet had struck a hard surface and broken before recovery. However, after comparing it against firearms provided for analysis, he found no match.
“The jacket was from live ammunition, but the bullet core was missing. When I compared it with the firearms presented for analysis, none matched,” he testified.
Mwandawiro explained that while three pistols were forwarded from the DCI armoury, the Ceska F7226 pistol listed by IPOA was not among them. Rifles like Chalbi and AK-101s were also excluded because they use different calibres. He concluded that the findings were inconclusive.
“The findings were inconclusive because the firearms supplied were of different calibres, and the bullet jacket did not match any of the pistols presented,” he said.
The court directed that the matter continue on September 25, 2025, when more witnesses are expected to testify.
Rex Masai was shot on June 20, 2024, along Moi Avenue as police engaged protesters opposing the Finance Bill. His death fuelled public anger and amplified calls for accountability over police use of force during the demonstrations.
