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?
Then be clear in what you’re saying, or better, don’t say anything, because no one asked about hypotheticals.