They looked for clues for the whereabouts of the woman's mobile phone which was switched off a few minutes after she left her office on the night of February 13, they said.
Chief Minister Jayalalithaa had yesterday transferred the investigation into the death of Uma Maheswari, an employee of Tata Consultancy Services, to the CB-CID.
Maheswari, a native of Salem district, lived in Medavakkam and had been working with TCS at nearby Siruseri since February 2013.
The autopsy revealed she had stab injuries in four places, which is believed to have led to her death.
The woman's body was found near her office premises near Siruseri in the city outskirts yesterday, nine days after she went missing.