The constable, identified as Bhaskar Baishya of 10th Assam Battalion, shot himself on his head last last night at the CM's official residence at Koinadhara here.
Baishya died on the spot and his body has been sent for postmortem.
The 32-year old constable, who hails from Sualkuchi in Kamrup (Rural) district, is survived by a wife and a child.
The reason for Baishya taking his life was yet to be ascertained, sources added.