Dhaka’s Women and Children Repression Prevention Tribunal Judge Tanjina Islam gave the order on Thursday with the convict on the dock.
Along with the death penalty, the convict Mohammad Zohirul Islam, 27, was also fined Tk 100,000.
According to case details, school boy Sifat Ali Tonmoy was kidnapped on Mar 26, 2012 when playing at the field of Darus Salam Government Primary School in Mirpur.
Hazrat Ali, father of Tonmoy, filed an abduction case with Mirpur police the following day.
Later, Tk 800,000 was demanded as ransom over phone. Detective Police traced the call and arrested Islam, a second-floor tenant of Ali on the next day.
Islam admitted that he had strangled Tonmoy since he was not paid the ransom.
Based on his confession, the body was recovered wrapped in a bag from inside the house.