Why did the stormtroopers kill the jawas and then make it look like the sand people did it?
Huh? Luke assumed sandpeople did it. Then Obi-Wan said that sandpeople walk in single file to cover their numbers, and that the track in the sand are shown side by side, aka Stormtroopers.* The Stormtroopers didn’t even try to make it seem as if sandpeople did it. Luke only assumed that since it’s implied Jawa’s and sandpeople don’t get along.
Luke Skywalker: It looks like the Sandpeople did this, alright. Look, there’s gaffi sticks, Bantha tracks. It’s just, I never heard of them hit anything this big before.
Obi-Wan Kenobi: They didn’t, but we are meant to think they did. These tracks are side-by-side. Sandpeople always ride single file to hide their numbers.