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?
Like you said, it’s hard to not be on security cameras, and they only shared the video of the attack that had a couple of frames of the upper half of his face. So they are looking for someone with the upper half of their face.
Oh. Sharing too much stuff as public information can actually make it harder to get a conviction if they do find the guy. It’s normal to not make public every single photo and video of a suspect. They’ll release some of the most likely info to help ID and find a person and keep the rest for the prosecution.