Is it technically possible?
It’s simple: Boris goes toward the sewer entrance and Willie just follows him and hits him.
The shadow that hits Boris seems to wear a hat and possibly a trench coat, just like Willie.
Means: Willie hits Boris with the whisky bottle
Motive: Willie kills Boris to get his money (and he does get his money)
Opportunity: WIllie and Boris are the only people there, nobody would see Willie committing the murder
Is it technically possible that the Murder was him?