The “court finds the murder most foul with its meticulous planning and execution,” the judge, Jessie Lessit, said on Friday.
Mwendwa, a motorbike taxi driver, accused lead defendant Frederick Leliman of shooting him for no reason at a traffic stop in 2015. At the time of his death, Kimani was working for International Justice Mission, a global legal rights group that helps investigate and document police killings and brutality.
Their bodies were later recovered from a river outside the capital Nairobi. The case caused outrage in Kenya, where police have faced frequent allegations of brutality and extrajudicial killings but are almost never charged.
Kimani’s body was found with wrists bound with rope. Three of his fingers had been chopped off and his eyes appeared to have been gouged out.
The judge singled out Leliman for acting “in flagrant abuse of his office” and masterminding the murder.
He was sentenced to death by the court, however, Kenya usually commuted death sentences to life in prison and has not carried out any executions since 1987.
The two serving police officers, Stephen Cheburet and Sylvia Wanjiku, and their civilian informant, Peter Ngugi, were given prison sentences ranging from 20 to 30 years.
Cliff Ombeta, a lawyer for the three officers, told AFP that all would appeal the sentencing. “This judgement cannot stand the test of any court of appeal judges,” he said.