Chennai: A week after the killing of a 13-year old boy in an Army premises here, Tamil Nadu CB-CID has cracked the case with the arrest of a retired Army officer who confessed his involvement in the incident.

The special team of the Crime Branch of CID police arrested the 58-year old Lt Col (Retd) Kandaswamy Ramraj and recovered the 0.3 mm rifle used to fire at Dilshan, who fell to the bullet when he trespassed into the army residential quarters to pluck almond fruits on last Sunday.

Briefing reporters on the breakthrough, CB-CID Additional DGP R Sekar, said Ramraj, who retired in April and was on extension, "has come out with the confession" and told police that he shot at Dilshan after getting annoyed over the boys from a nearby locality frequenting the campus to pluck almond.

The weapon was recovered from Cooum river near the Napier bridge in Chennai, he said.

Sekar said the probe zeroed in on Ramraj after questioning several persons, including Army personnel, with the "full cooperation" of the Army after collecting all evidence.

Ramraj, a native of Madurai, had been charged with section 302 of IPC (relating to murder) and would be produced before a court here.

Dilshan who was residing in the Indira Gandhi Nagar locality adjacent to the army quarters in the Island Grounds locality, fell victim to a mysterious bullet when he tried to pluck almond fruit from the army residential area. The victim's family had alleged he was shot by Army personnel.

The postmortem report had earlier established that a bullet injury had killed Dilshan when he scaled the Army campus.

An Army officer in the rank of Lt Colonel and some others have been questioned in the last few days in connection with incident.