Maybe I’m just face-blind or being dense but the photos from the scene of the crime look like a different dude than the ginning hostel check in guy. The jackets and backpacks are different. Although people can have multiple jackets and backpacks. We don’t see much of the shooters face but the eyebrows look different. Although, people can pluck/shave eyebrows. I guess the happy hostel guy would have come forward and been like “WTF?” and “I have an alibi” if it wasn’t him?
Unless he put the clothes in the backpack and put all of that into the other backpack, Backpackception! It sounds really silly though, like he purposely changed his clothes ever so slightly, just enough that a few people would call it out, instead of changing into a completely different outfit, which would’ve been more effective IMO. It’s just alot of work for little benefit, people come up with the weirdest theories.