The miscreants escaped from the spot after the shooting. "We are investigating the incident," said Sunil Kumar, Kokrajhar superintendent of police.
A PTI report said that the slain person was a former member of the Bodo Liberation Tigers (BLT), a militant group which was disbanded after it signed the Bodoland accord with the Centre in 2003. Leaders of the then BLT now governs the BTAD through the Bodoland Territorial Council (BTC).
Sunday's shooting came a few days after a bamboo trader was killed and another injured when armed miscreants open indiscriminate fire on them. The victim was identified as Lalji Sheikh.
The two killings raised the spectre of fresh violence along the troubled north bank of the Brahmaputra, where a series of killings and counter-killings had triggered Bodo-Muslim clashes in July-August last year.
The clashes had left nearly 100 dead and many more injured besides displacing over one lakh from their homes.