I have all the books I could need, and what more could I need than books? I shall only engage in commerce if books are the coin. -- Catherynne M. Valente
It just doesn't make any sense. Someone who would be all excited about committing a mirder isn't going to wait until the one day that it's legal.
I haven't seen the movie, but I imagine the penalties are extraordinarily stiff for crimes outside of the free day and that there is some sort of police state thing going on. Plus, it's all crimes, not just murder.