A neighbour, Richard Mwangi, said they heard the killers ordering him to open the car door before shooting.
"We heard, 'open the door', several times and later we heard two gunshots. After the first one we heard a shattering sound of glass breaking.
"We could not get out of our houses. We only walked out when he heard the thugs vehicle leaving," he said.
Mnyolmo said when neighbours including family members came out, they removed him and rushed him to Kikuyu Hospital where he was pronounced dead on arrival.
"So far no one has been arrested but we are conducting investigations into the incident," the police commander said.
She said the thugs stole his mobile phone only, adding that further investigations will unveil if there was anything else that was stolen.
A human rights defender organisation Haki Africa condemned increasing cases of people being killed mysteriously.
Haki Africa rapid response officer Peter Onjiro asked the DCI to investigate and establish the motive of the murder and arrest the killers.
"We are concerned by the high number of murder cases. The government must be firm in dealing with this painful wave of mob violence and public persecutions," he said.
However, residents have asked the government to come up with a strategy of improving security since cases of insecurity are rampant in the area.
Resident James Karanja says they feel that their village is neglected since it lies between Limuru and Kikuyu constituencies.
"We need police to intensity patrols since thugs have discovered that police stations and patrol bases are far from this village. We need one in this area," Karanja said.
(Edited by Bilha Makokha)
