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?
Can’t say personally seen any of the security footage but from the sounds of it this guy was mingling with the crowd and not drawing attention to himself as well as able to book it down the alleyway. It’s not improbable that he’s terminally ill himself, but it’s hard for me to believe he’d be at a stage the doctor(s) said he was incurable/insurance denied him but still not far enough along it’s not affecting him in anyway noticeable way.