Additional District and Session’s Judge Md Anwarul Haque delivered the verdict.
The condemned convicts are Md Moslem Uddin, 45, son of late Saheb Uddin, Mostafizur Rahman and Md Mamunur Rashid, sons of Md Jafar Uddin of Khayerbari village in Birampur upazila.
The lifer is Sohel Rana, son of Muzibur Rahman of the same village.
The court also acquitted another accused as allegations brought against her were not proved.
According to the prosecution, the trio hacked Wakil Uddin Mondal to death on June 25, 2011, when he tried to settle a land dispute between his brother-in-law and the convicts at Khayerbari village.
The following day, the victim’s wife filed a case with Birampur Police Station over the murder.