Uwaila, a 35-year-old man, has been arrested by the Edo State Police Command, for shooting his wife and two sons dead.
The incident happened on Sunday at Ovbiogie village in the Ovia North-East Local Government Area of the state.
Security agents were said to have evacuated the corpses to an undisclosed mortuary.
The suspect, who is now in police custody, said his wife accused him of having extramarital affairs.
He added that his wife threatened to also go out with other men.
Uwaila said he drove out of the house in anger and came back to see that his wife had locked herself and his sons inside one of the rooms.
He added that he shot through the door and the bullets hit them on the bed.
The state Police Commissioner, Hakeem Odumosun, who visited the scene, said the suspect would be charged to court after investigation had been concluded.