"We have registered a case under sections 302 (murder) and 307 (attempt to murder) of the IPC against Sudesh," said a police officer.
Sudesh, 36, the wife of librarian Anil Sharma, works as a nurse with Delhi government's Acharya Shree Bhikshu Government Hospital.
Police said Sudesh killed builder Manoj Taneja's wife Reena in her Moti Nagar house in west Delhi. She also killed her own son, Aarav, three, and attacked her daughter, Komal, 17, before injuring herself. Komal is out of danger.
According to deputy commissioner of police Ranveer Singh, Reena, 44, entered the librarian's house and engaged in a heated argument with Sudesh over some issue.
"During the argument, Sudesh attacked Reena with a sharp-edged weapon that led to Taneja's death. Later, she stabbed her own son, Komal and herself," Ranveer Singh told IANS.
The incident came to light when neighbours learnt about the stabbing incident around 2.40 p.m. Thursday when they heard Komal screaming for help in her balcony.
"The neighbours informed police as Komal was bleeding," said Singh. By the time police arrived at the spot, the toddler and Reena had died.
The officer confirmed that police came to know about the sequence of events from Sudesh who gave a statement before being hospitalised.
The police said they found an anonymous suicide note written in blood that blames builder Manoj for the incident.
Police are exploring an extra-marital angle in the murders.
"Sudesh attacked her own son and daughter because she was worried as to who would take care of them after her as she would be jailed following Reena's death," said the officer.
He said Sudesh, undergoing treatment but out of danger, will be arrested after she is discharged from the hospital.
"We have also questioned Manoj and Anil to ascertain their relationship," said the officer.
--IANS (Posted on 19-10-2013)