Al Capone, or "Scarface" a Brooklyn native, showed no mercy to anybody in order to capture all of the dark power and wealth in Chicago during the era of Prohibition in the United States.
To begin, Capone was notorious for his lucrative bootlegging businesses and speakeasy establishments. Both activities appear to be frowned upon given the country's state, but overall do not seem monstrous or harmful. Right? That is because these illicit activities allowed Capone to conduct much worse. For instance, "over the years, Al Capone consolidated control over most of Chicago’s crime rackets by ruthlessly gunning down his rivals. In 1924, authorities counted some 16 gang-related murders; this brand of slaying continued until 1929, reaching a high of 64 murders in one year during that time. " With a double digit kill count, it is clear Capone lacked morality and was ruthless with his actions. Capone inflicted harm and death onto neighbors and strangers and did not show any remorse. 

With all of the Mob power, Capone's hubris was high. Capone felt invincible and believed he could act as he wished and live above the law.
"On May 17, 1929, Al Capone and his bodyguard were arrested in Philadelphia for carrying concealed deadly weapons,"  Capone was then released from jail nine months later and his illicit activities swiftly continued. Again it becomes apparent how lethal Capone was to society. At any moment, Capone was prepared to murder whomever crossed him. This extreme power and feeling of invincibility is detrimental to society because it allows mobsters like Capone to feel unstoppable. 

At the end of Capone's life, he fell to syphilis of the brain and "in 1946, his physician and a Baltimore psychiatrist, after examination, both concluded Capone then had the mentality of a 12-year-old child."  Capone's suffering internally and mentally is symbolic to his monstrosity. For decades, before the illness, Capone inflicted pain on others without feeling guilt and remorse, just like a 12-year-old child that does not yet understand the real world. As an adult, this capability to destroy without regret is inhumane and detrimental to society. Therefore, Capone dying with the mentality of a 12-year-old child is symbolic. This vulgar adult was a dangerous deviation from the norm and died in a manner to highlight that. 

For a visual experience of Capone's final years consider viewing the trailer for the movie Capone here.