The sub-inspector has surrendered himself to the police.
A police officer shot and killed a retired policeman in Assam's Dhemaji district on Saturday.
According to reports, Alok Konwar, a sub-inspector at Dibrugarh Police Station, killed the retired police officer Amulya Barua with his service pistol.
The sub-inspector reportedly left Dibrugarh this morning after emergency night duty, travelled to Dhemaji, and fired three times at Amulya Barua, a retired police officer from Arunachal Pradesh.
The police suspect that the shooting might have taken place due to a personal dispute.
"Alok Kumar has already surrendered before police after committing the crime. We have launched investigation into the case," said a police official on the shooting.