The accused have been identified as Agam Kohli, who is pursing a BA from Delhi University, and Gagandeep.
The maid, Inderjeet Singh (45), was yesterday killed while the baby she used to look after was also found injured in a flat in house No.B-21 at Rama Park in West Delhi's Uttam Nagar, police said.
"During interrogation, Agam revealed that he was earlier working in a placement agency on the first floor of building number B-21, Rama Park.
The accused hatched a plan to rob the house and used a BSES electricity disconnection notice as a ruse to gain entry into the premises, police said.
According to police, the duo also assaulted the two-year- old kid whom Singh used to look after.