Malep Opisa beat the infant Lucizia Nzuki with a blunt object on the head, before leaving her bleeding on the sofa set at Bathi village, Kijabe Ward.
According to the police, the suspect had only worked for a week.
The child's mother works in Nairobi while the deceased was staying with her grandmother.
Lari OCPD Isaiah Odhiambo said the baby was rushed to AIC Kijabe Hospital, but died on arrival.
The grandmother Lucy Njuguna said she left home at 10 am to the farm but when she returned home at 5 pm, she realised no one was in the house.
She knocked at the door and no one answered her. She noticed the door wasn't closed and she pushed it and saw her granddaughter with blood in the head Odhiambo said.
Speaking at his office at Lari police station, Odhiambo said the baby had swollen bruises on the head and had blood in the eyes, an indicator she had been tortured and beaten.
He said police are pursuing the suspect who escaped after the incident.
The child's body is lying in the hospitals mortuary awaiting an autopsy.
We have seen children being mistreated, beaten and even denied food by house helps. This is very unfortunate since they are innocent. They should have mercy and put themselves in their mother's shoes, would they want theirs to be killed, tortured or beaten by house girls? Robert Kimani, a resident asked.
Courtesy Geroge Mugo/The Star