A police officer attached to IG Joseph Boinett's office was on Wednesday shot dead by his colleague who later killed himself.
James Makhokha, a police constable at Jogoo House, was shot by Constable Patrick Kimani - his friend and drinking buddy.
Kimani is attached to JKIA police station.
The two were at a bar in Embakasi when the incident happened at around 1.30 am.
Kimani also shot and injured a third police officer, Dominic Ngetich, who attempted to intervene when a verbal altercation started between the two.
Ngetich was rushed to Bliss hospital with a bullet wound on the right shoulder. He was later moved to Nairobi West Hospital.
A Jericho pistol with nine rounds of ammunition was
recovered at the scene.
In October 2016, a Recce Squad officer used an M16 rifle to fire 53 bullets at his girlfriend before turning the gun on himself in Ruiru.
The US-trained commando Kennedy Mwarabu shot Nthenya Katheka after she allegedly told him she was leaving him to marry someone else.