"This attack was committed in the framework of the resistance," said Ayman Taha, a spokesman for the group. "This is a reaction to the continuing occupation and the continued building of settlements. This is a natural reaction, especially against the backdrop of Israeli attacks. We are a people occupied, and it is our right to defend ourselves and to act in every way and with every means at our disposal to defend ourselves," Taha said.
Let me paraphrase – the sight of their yarmulkes made him do it. May G-d avenge their blood.