Policeman Fredrick Ole Leliman was on Friday sentenced to death for killing lawyer Willie Kimani and two others in 2016.
Justice Jessie Lessit said Leliman was the mastermind of the foul murders.
Police officers Stephen Cheburet and Sylvia Wanjiku were sentenced to 30 and 24 years in jail respectively. Police informer Peter Ngugi was jailed for 20 years
Cheburet, Leliman, Wanjiku and Ngugi were convicted on July 22, 2022.
Justice Jessie Lessit, now a judge of the Court of Appeal, found them guilty of killing rights lawyer Willie Kimani, his client Josephat Mwenda and taxi driver Joseph Muiruri on June 23, 2016. The bodies of the three men were found stashed in gunny bags in Ol Donyo Sabuk, Machakos County, on July 1, 2016.
They had been dumped in River Athi and were found more than a week after the men were reported missing.
