[Inettypofonee]

Bangkok police have arrested a 55-year-old woman on suspicion of killing her 13-year-old grandson late last week in their room off Srinakarin Road.

A DNA test led police to detain Somjit Jampadee, the grandmother, at Building D of Yong Charoen Complex on Supapong 1 Road off Srinakarin Road in Prawet district yesterday for killing the boy, Atthasit Leelertyuth.

His body, dressed in a football jersey and shorts, was found on the fire exit stairs of the building at about 11.30am on Friday. There were wounds and bruises to his left eyebrow, his neck, and the back of his head.

Police believed he was hit with a hard object and had died no more than 20 hours previously.

As no shoes were found with the body, police assumed the boy had been killed in the building where he lived with his maternal grandmother. However, she initially insisted the boy had left their room after she told him to behave.

Police said a DNA test on hair found in the boy's hands revealed it was Mrs Somjit's.

Police said the woman then confessed to killing her grandson. Police said she told them the boy had tried to assault her when she scolded him about his fights with schoolmates and his addiction to computer games.

She said she hit her grandson once with a bat on the back of his neck in self-defence, which knocked him out. When she could not find a pulse, she realised he was dead.

She allegedly tried to conceal her crime by dragging him out of the building but gave up because he was too heavy. She then returned to her room.

Atthasit was cremated at Wat Ton Sai temple on On Nut 29 Road in Suan Luang district last Sunday and Mrs Somjit was among his relatives and schoolmates at the ceremony.