A video showing a teenage boy being beaten to death by a group of men, who filmed themselves jeering and laughing as they carried out the attack, has sparked widespread outrage in Bangladesh.
According to the autopsy report, Samiul Alam Rajon died of brain haemorrhage and his body bore about 64 injury marks, reported The Daily Star.
The 13-year-old was accused of stealing a bicycle rickshaw van in the north-eastern city of Sylhet.
After the video showing Rajon getting beaten by a metal rod went viral, thousands in Bangladesh have been demanding justice for the act.
A special police squad has been formed to probe the killing.
Meanwhile, three people have been taken into custody, including the main accused, who fled to Saudi Arabia after the attack.