The police arrested the Myanmar maid from outside the residential unit at Block 791 Choa Chu Kang North 6, where she allegedly killed the 70-year-old woman.
The suspended police officer was sentenced to 1-year imprisonment under charges of being a member of an unlawful society, including two additional charges.
After police received a complaint from the victim, five girls and two boys, aged between 15 and 19 have come forward to assist the police investigation.