The Uttar Pradesh police will conduct a narco test on the main accused in the killing of Sheeba Thomas and injuring of retired Major General TJS Gill in Noida on April 9.

"The main accused in the shooting that killed Sheeba and injured Gil and the looting of three vehicles, Lakshman alias Lakhi Yadav, has been remanded in police custody for seven days," DGP Vikram Singh said.

"We will conduct a narco analysis on him to elicit more information," he added.

A warning has been issued to Additional Superintendent of Police J Ravindran Gaur, who was in charge of control room at the time of the incident, and Deputy Superintendent of Police T Sen for not responding promptly, he said.

The station house officer in Sector 49 in Noida, Amardeep Lal, and sub-inspector P Singh have been suspended for laxity in performing their duties.

The DGP said that Yadav is at present being interrogated by senior police officials.