A prison officer is being held in police custody for allegedly shooting dead his girlfriend and one-year-old son. The officer was attached to Waita GK Prison in Mwingi, southeastern Kenya. David Nduati was reported to have killed his girlfriend Joyce Mwende,30, and his son Raji Mwende before surrendering his G3 rifle to officers manning the premises' main gate. Reports indicated that the victims had just arrived at the officers’ house from his in-laws when the incident happened. "The duty officer received information that Pc David Nduati Kimani had surrendered his G3 rifle to the officers manning the main gate, and he confessed that he had killed someone and left. “The duty officer proceeded to the scene of the crime that’s Pc David’s house, together with two guard commanders and found that one Joyce Mwende Ngui and her son Raji Mwende a juvenile aged about 1-year-old had been shot dead by Pc David Nduati Kimani inside his house. They arrested him while he was about to escape,” read the police report. Six spent cartridges were recovered inside the house and a G3 rifle S/no. 081551 loaded with a magazine of 11 rounds of ammunition were recovered and kept as exhibits. The motive for the killings is still unknown. The incident happened on Tuesday night.