Additional District and Sessions judge Choudhary Vijendra Kumar found the three accused guilty of the murder of Akash Kumar alias Arvind, a resident Kadamkuan area and awarded them lifers.
Those convicted are Atul Kumar Verma, Shankar Prasad Jaisawal and Shakti Paswan.
Aakash was kidnapped for ransom of Rs five lakh on January 7, 2008.
The body of the minor boy was recovered from Parsa Bazar area adjacent to the village of Shakti Paswan a few days later.