Public prosecutor Badrul Islam Chowdhury said on 6 August that the Sylhet Metropolitan Child Violence Suppression Tribunal had sentenced Jakir Hossain to death and ordered him to pay a fine of 500,000 taka.
He added that the two other defendants, Jakir's brothers Zainal Abedin and Md. Abul Kalam, were acquitted because the court found no evidence of their involvement.
Judge Abu Ubayda of the tribunal pronounced the verdict at about 11:30 am.
The case stemmed from the death of four-year-old Fahima Akter on 7 May in Sonatla village under Sylhet Sadar's Kandigaon union, and a murder case was registered at Jalalabad police station the next day.
Court proceedings described Jakir, a neighbour, luring the child to his home, sexually assaulting her, strangling her, keeping her body in a suitcase for two days and dumping it in a ditch at Badaghat.
A charge sheet naming Jakir and his two brothers was submitted about 33 days after the incident, and the trial began on 1 July.
The verdict came after about a month of trial proceedings.