PETALING JAYA: A bout of depression is believed to have driven an Indonesian maid to kill her employer's two sons, before taking her own life. The woman, who is in her 30s and known only as Agnes, was said to be a devout Christian and a loving babysitter to 18-month-old Melvin Selvam Joseph and his stepbrother Koay Jia Hong, aged five. But on Tuesday, she allegedly slit the throats of the two boys before doing the same to herself at their home in Taman Seri Putra, Sungai Buloh. Sungai Buloh police chief Supt Junaidi Bujang said investigations showed that the maid had showed no resentment towards her employer and was happy during her two years working for the family. "We believe she may have been depressed by her (perception of a) bleak future, being an illegal immigrant (and) lonely without her own family. There is no evidence pointing to a third party being involved in the killings. "She was a reserved and quiet person and neighbours told us that she was treated well by her employer and was happy working. "The family absolutely could not have known of this tragedy brewing as the maid was her usual self all the time. We found out that she was good with the children and often prayed and read the bible. It baffles us that a God-fearing person could be driven to this," he said, adding that police have ruled out robbery as there were no signs of forced entry. He said the dead children's grandmother had returned home at about 7.30pm to check on them when she found the bodies of the children and the maid in the kitchen and upper floor of the double-storey house. Police recovered three kitchen knives that are believed to be the murder weapons and a post mortem report revealed that the cause of death of all the deceased were the result of knife-inflicted wounds to the neck. The maid's 27-year-old employer, who runs a restaurant with her parents and sisters, had left the house for work at about 8am. It is learned that her older son was from her first marriage. About two years ago, the woman remarried and had her second son with a 46-year-old information technology consultant but barely months later, the couple separated.