"He has not talked and the motive is not clear," Chelimo told journalists.
But Mr Charles Owino, deputy spokesman, told Reuters: "He went from one bar to another and was shooting indiscriminately. Apparently, he was looking for his girlfriend after he left duty."
His first stop at a beer garden, specialising in second generation brews was a joint christened Coconut Bar.
In full uniform and rifle in hand, he stood at the entrance and asked where the lady was. A waiter who cared to respond that she was not at the facility became his first casualty; shot in the head, as other revellers scampered away to safety.
The officer then pulled his trigger a second and third time, killing two other people, one of them another barmaid.
With three down, the constable moved to Wakyai Bar, where many patrons had left for the night, but there were a few drinking inside. "Fungua, fungua, mimi ni polisi," (open the door. I am an officer) shouted Karanja, pretending he was on patrol.
The bar attendant opened the door unaware death had knocked. Karanja pumped bullets into his chest, killing him instantly.
But it was at the third spot, a bar called Club The Shrek, that he exhibited his worst fury. Behaving like a bloodhound, he shot at two APs, who had allegedly walked out of the bar after they heard his earlier gunshots.
Patrons who were inside fled as the barman rushed to close the door where the lone gunman stood after executing the two officers. The barman was too late to shut him out.
Meanwhile, 12 people managed to hide in pit latrines at the back of the bar. As it were, their quick action saved them from death. Six revelers were not as lucky, as by then, Karanja had walked in, gun blazing. One by one, he shot five men dead before engaging the last person — a woman — in a short conversation.
Those who hid in the latrines said they heard a woman who they identified as Ng’endo pleading with the officer to spare her life as she had a young child to take care of. She did not convince him.
In a split second, her lifeless body lay by the side of four men who were in her company.
Rashid Kinyua, who took cover in the latrine, said the gunman was a known figure in the township, where he had worked for two years. Another witness claimed he rushed to the police station, 200m from the scene of killings, and alerted officers.
"But he only asked me what weapon the gunman was carrying. Since I did not know, I went home," said Michael Njeru.
A guard at a local financial institution allegedly called the station, but there was no response. Marigu survived because it is said she fled when informed he was looking for her. He surrendered himself at Siakago Police Station with his weapon.
In the morning irate residents stormed the police station baying for Karanja’s blood.
They also wanted to know why it took Chelimo and area police chief Jecinta Odhiambo long to address them. Karanja was transferred to the Embu Provincial CID officers for further interrogation.
Five men, three women and APs went down as his victims, and today, their relatives are mourning their sad loss.