Interesting. Up until the 90's or so killings, publically at least, were quite a regular occurance, right? Weekly or at times almost a daily basis.
It was never daily. The only example when I can think of it being weekly was Chicago during Prohibtion (something like 500 killings over 10 years or so, so an average of about one per week).
Maybe if you added all the hits going on nationwide during prohibition, it might average out to roughly daily hits, but I doubt it.
Today, if you included street gangs as "organized crime", they might be killing each other on a daily basis, but I don't think that's what you were asking.