I don't see how you can call it a brutal murder.
True he was a paralytic (quadraparaltic?) come out of morning worship. But he was also a murderer, a terrorist, and a combat target. He murdered (directly or indirectly) women, children, babies, civilians. He was a terrorist. He knew he was a fair target in war, and ultimately he got what he deserved (IMHO).
And how can you arrest him anyway? Just walk up to him with a pair of handcuffs?