" Back in those days there was less violence among Chicago's criminals. Obviously there were bombings and beatings but rarely a murder.So my point is that in those days there was a more of a "good business climate" between the operators,like in these two previous examples, rather than murderous rivalry."

Chicago always had a particular high murder count even then depending on accurate reporting. Before the rise of Prohibition there was in the mid to high 100s. After Prohibition it basically doubles.

@Furio