The court of 9th Additional District and Sessions Judge Surendra Sharma pronounced Prabhunath Singh and his brothers, Dinanath and Ritesh guilty yesterday of killing the erstwhile MLA in 1995.
The court will decide upon the quantum of punishment to the trio on May 23, the judge said.
Prabhunath and his two brothers were taken into custody soon after the judge held them guilty and were sent to the Hazaribag central jail.
The case had been registered on the basis of the statement of the slain MLA's widow Chandni Devi.