The Kansas City gang, like other criminal organizations around the country, gained immense wealth and power during Prohibition by bootlegging alcohol.
Most of murders that occurred during this era were committed by the mob to protect their bootlegging operations in the city and surrounding area.
The largest alcohol stills were located in the heavily wooded and inaccessible areas on the Missouri River east of the city limits.
Stills were also stationed in well-disguised underground facilities in the Little Italy section on the North Side of Kansas City.
At one point, Federal Prohibition Agents calculated that DeMayo was personally grossing more than $1,000,000.00 annually from the still operations.
Two weeks after DeMayo's conviction, John Lazia assumed control of the Kansas City criminal organization.