According to locals, a thief sneaked into the school premises on Wednesday night and was apprehended by Shuku.
The thief stabbed Shuku with a knife, which caused excessive bleeding and led to his death.
Dinajpur ASP Mahfuzur Zaman Ashraf said: “Police went to the spot at night. Shuku was stabbed by a thief and the cause of death is excessive bleeding. Locals took him to Dinajpur Medical College Hospital where he was pronounced dead by the doctors who were on duty.”
Shuku was the son of late Lokkhon Shoren from Awliapukur. He had joined the school as a night guard two days ago.
Whip Iqbalur Rahman, RAB, PBI members and DB police went to the spot on Thursday morning.
Iqbalur Rahman said: “We have given the victim's family Tk20,000 and the government will provide them with further financial assistance.”
Anyone involved with the killing will be brought to justice, he added.