The officer is said to have shot and killed  Moses Kinyanjui Wanyoike at Crescent Island in Naivasha. [Courtesy]

A High Court has sentenced a police officer to 20 years in prison for killing a fisherman eight years ago.

Police constable Evans Maliachi Wiyema was in February found guilty of killing Moses Kinyanjui Wanyoike who was fishing in Lake Naivasha.

Justice Richard Mwongo, however, noted that Wiyema could serve ten years if he attends a rehabilitation programme for three years.

“The court shall in the fifth year of his sentence review the offender's conduct and sentence based on reports of the probation officer and the prison service,” he said.

Mr Mwongo ruled that the officer misused his power and authority when he shot the fisherman at close range.

Fishermen at Lake Naivasha. [Antony Gitonga, Standard]

He further noted that the officer failed to report the incident to his seniors.

The officer is said to have shot and killed Wanyoike on July 27, 2014, at Crescent Island in Naivasha. The fisherman was with his friends Johnson Ndichu and Douglas Tutu.

In mitigation, the former anti-stock theft officer called for leniency saying that he regretted what he did.

The International Justice Mission (IJM), which represented the family of the deceased, termed the ruling as a major win.

Benson Shamala, country director at IJM Kenya, said the court’s decision was a big step in holding errant police officers to account.

He noted that Wanyoike was one of many young men killed in unclear circumstances. He added that they would continue demanding accountability for any police officer who violates the law.