Judge Manoj Kumar Mishra also imposed a fine of Rs 20,000 each on the convicts after holding them guilty under section 364 (Kidnapping or abducting in order to murder).
According to government lawyer Harsh Sharma, the boy was abducted by the four over old enmity of a land dispute at Khatoli town in the district on May 15, 2009.
It is suspected that he was murdered after the abduction, but his body was not recovered.