Muhammad Abdullah Jabar, the brother of former Meretz MK Hussniya Jabara was killed overnight Sunday by a bomb that was thrown at his house in Taibe.
67-year-old Jabar went outside to check what had been hurled at his home and the device exploded in his hands.
Jabar was taken in critical condition to Kfar Saba's Meir Hospital, where he died of his wounds.
Police launched a murder investigation.
In other Sunday night violence, a Border Police officer allegedly murdered a 40-year-old man in Kibbutz Zikim, in the South.
Police said that from the preliminary inquiry, it appears that an argument erupted between the two, during which the victim threatened the officer with an iron rod, before the suspect shot him dead.