Chennai, July 9: A retired army colonel has been identified as the person who shot dead 13-year-old Dilshan in an army residential colony last Sunday.

The breakthrough and the formal arrest will be announced by the crime branch tomorrow morning.

The retired colonel and a serving officer topped the suspects’ list in the case.

“We have also seized the murder weapon,” a senior police officer of the investigative team said.

Investigations revealed that the bullet that killed the boy had not been fired from the service revolver of Lt Col Ajay Singh, the serving officer who was also being probed.