This couple was murdered by someone who, if given the opportunity, would shoot every single Jew on Planet Earth. He killed them because he thought that they were Jewish
No, this murderer had the opportuity that evening to shoot many more, but he said his goal was only to protest the evil zionist regime. He hid with his gun amongst the panicking survivors who did not know he was the shooter until police came and he volunteered himself as the shooter.
So, no, this was an evil political statement not a “kill as many jews” act.
There is also no reason to think that he cared if they were Jewish or not. He, along with many Jews, hates Zionism and the evil that regime does in the world.