In the spring of 1924, Johnny Torrio and Al Capone were the reigning kings of the Chicago underworld, but trouble was coming, and most of it was being caused by Dion O’Banion.

Dean Charles O'Banion was born in 1892 in the small Central Illinois town of Maroa. His father, Charles, was a barber by trade who hailed from Lincoln, Illinois, and his mother, the former Emma Brophy, was the Chicago-born daughter of an Irish immigrant father and American mother. She had been just eight months old when the Great Chicago Fire had leveled the city in 1871. Charles and Emma had married in 1886 and moved to Maroa the following year, where Charles' parents lived. Dean spent the early years of his life in Maroa but soon after the birth of his sister, Ruth, his mother contracted tuberculosis and died in 1901. Dean was only nine years old at the time and the loss was a devastating one to both he and his remaining family. They packed up and moved to Chicago, where Emma's parents had a place for them. Dean (soon to be known as Dion) saw the end of his innocent years. The hard times, and the legend, were about to begin.

Upon moving to Chicago, O'Banion found himself turning to the streets for a playground. He became involved with a street gang known as the Little Hellions and began picking pockets and rolling drunks. At the same time, he sang in the choir at the Holy Name Cathedral and, on Sunday, he served as an altar boy. Some of the priests at the church believed that perhaps his devotion might lead to the priesthood but O'Banion soon learned to ration his religion to Sundays and to devote his remaining time to robbery and, as he reached young adulthood, to burglary: "a man's profession." He soon became friends with a collection of safecrackers and petty criminals like George "Bugs" Moran, Earl "Hymie" Weiss, Vincent "The Schemer" Drucci and Samuel "Nails" Morton. With these men at his side, O'Banion put together one of the most devastating gangs in Chicago. They centered their activities on the North Side, around Lincoln Park and the Gold Coast.

O’Banion earned a reputation as a daring, ambidextrous, flower-loving, good-natured killer, who wore a carnation in his buttonhole and carried three pistols stowed away in special pockets that had been sewn into his suits by his tailors. Chief of Police Morgan Collins called O’Banion “Chicago’s arch criminal” and declared that he had killed, or ordered killed, at least twenty-five men. But he was never brought to trial for any of these murders because, politically speaking, he was only slightly less powerful than Torrio and Capone.

In 1922, O’Banion bought a half interest in William Schofield’s flower shop on North State Street in downtown Chicago. It was located directly across the street from Holy Name Cathedral, where O’Banion once sang in the choir. As gangland’s official florist, he sold thousands of dollars’ worth of flowers to the friends and foes of slain gunmen, for it was considered good underworld etiquette to send expensive floral tributes to the funeral of your victim. Even without his gangland business, ownership of the flower shop would have made O’Banion wealthy. He had considerable business ability and a consuming love for flowers. He had a knack for making beautiful arrangements and his bouquets were considered works of art.

O’Banion also had a grievance against Torrio’s allies, the Genna brothers – Sam, Jim, Pete, Angelo, Tony and Mike, who were known as the “Terrible Gennas.” O’Banion claimed that the Gennas were moving in on his territory and flooding it with bad whiskey that they were selling for $3 per barrel. O’Banion was used to get $6 to $9 for his barrels, but they were of much better quality. He demanded that Torrio move the Gennas back to the West Side and when Torrio told him that he couldn’t force the brothers to move, O’Banion angrily threatened to do it himself. This was a task that no one but the fiery O’Banion would have dared for the Gennas and their gunmen were among the most feared gunmen in the city.

To show his contempt for the Gennas, and for Torrio’s leadership, O’Banion hijacked a Genna truck that was loaded with more than $30,000 in whiskey. The Gennas immediately made plans to retaliate but were restrained by Torrio and Mike Merlo, the president of the Unione Siciliana, one of the most powerful men in Chicago. He was an important figure and among his countrymen, his word was law. He was closely associated with Torrio, Capone and other Sicilian and Italian gangsters but took no part in gang wars and was strongly opposed to murder. Both he and Torrio believed that peace could be made with O’Banion without violence.

Through political connections, O’Banion had learned of the raid and had taken advantage of the knowledge to unload his share of the brewery on Torrio and Capone. O’Banion also knew the prosecution would be handled by the U.S. District Cort and that Torrio’s influence did not extend to the federal level. He knew he would be fined but he knew that Torrio would be in much deeper trouble.

Among Torrio’s dominant traits, which accounted for his success as a criminal, was the ability to control his temper. Undoubtedly, he hated O’Banion but he went about his business as though nothing had happened, since aware of the fact that killing O’Banion would result in a bloody war, which would be bad for business.

But O’Banion soon made things worse. He was amused by the “prank” that he had pulled on Torrio but a shrewd Hymie Weiss urged him to make peace with Torrio and the Gennas. O’Banion laughed at the idea, calling them “gutter rats” and saying with contempt, “To hell with them Sicilians!” This phrase, repeated by O’Banion gunmen as a bit of clever repartee, signed O’Banion’s death warrant, for to Sicilians and Italians alike it was a deadly insult.

Several times during the summer of 1924, the murder of O’Banion was planned by Torrio, Capone and the Gennas, but each time they were stopped by Mike Merlo, who still hoped for a peaceful settlement. But Merlo died from cancer on November 8, 1924 – and two days later, Dion O’Banion lay dead among his flowers.

Merlo’s funeral was an imposing event. More than $100,000 worth of flowers were sent to his home by friends and they filled not only the house but the lawn outside, as well. The most impressive of these pieces was a statue of the dead man, made entirely of flowers, which stood twelve feet high. Many of the flowers came from O’Banion’s shop, including a $10,000 order from Torrio and an $8,000 order from Capone. 

The three men walked abreast and approached O'Banion with smiles on their faces. The man in the center was tall, clean-shaven and wearing an expensive overcoat and fedora. It was determined years later that this man was New York mobster Frankie Yale. The other two, believed to be John Scalise and Albert Anselmi, were shorter and stockier, with dark complexions.

Crutchfield heard the man thought to be Frankie Yale reply, “Yes, for Merlo’s flowers.” He then stepped closer to O’Banion. Yale grabbed the other man's hand in greeting and pulled O'Banion toward him. The two men at his sides moved around him and drew pistols. Then, at close range, Yale rammed his own pistol into O'Banion's stomach and, holding his arm in a vice-like grip, opened fire. The other two men also fired their weapons and the bullets ripped into O'Banion. Two slugs struck him in the right breast, two hit him in the throat and one passed through each side of his face. The shots were fired at such close range that powder burns were found at the opening of each wound. From that point on, this method of murder became known as the "Chicago Handshake."

O'Banion fell, dead on his feet, into a display of geraniums. The gang leader had carried three pistols on his person at all times but they were unfired, not even drawn. The three men fled from the store and climbed into the car outside, which drove slowly away from the scene.

The Genna brothers, Capone and Torrio were all arrested on suspicion of homicide but were soon released after supplying airtight alibis. Frankie Yale was arrested at the La Salle train station, departing for points unknown, but he was also released. The investigation, headed by ace Detective Captain William "Shoes" Shoemaker, went nowhere.

At an elaborate funeral service, O'Banion's friends filed past his body, tough gangsters weeping as they walked into Sbarbaro's Funeral Home. He was placed inside a $10,000 bronze casket that had been fitted with bronze and silver double walls. A heavy plate glass window had been fitted over O'Banion's patched-up face and his men could peer down and see his head where it reclined on a white satin pillow.

O'Banion's funeral was the most lavish in Chicago gangland history. The hearse was led to Mount Carmel Cemetery by twenty-six trucks filled with flowers, worth more than $50,000. The scene at the cemetery was even more bizarre. On one side of the grave, lowering the body to rest, were O’Banion’s friends, Hymie Weiss, George Moran, and Vincent Drucci; on the other, Al Capone, Johnny Torrio and Angelo Genna. The men glared at one another, but no words, or violence, were exchanged.

Cardinal Mundelein had refused to allow funeral services to be held over the dead gangster, but at the grave, a priest who had known O’Banion since childhood recited a litany, a Hail Mary and the Lord’s Prayer. The gangster was originally buried in unconsecrated ground but was moved five months after his death to his final resting place. The circumstance of the move prompted Captain John Stege, an honest cop who battled gangsters for years to say, “O’Banion was a thief and a murderer, but look at him now, buried eighty feet from a bishop.”

But some might say that O’Banion did not rest in peace. His murder began the most violent, bloodiest time in Chicago’s history, leading to hundreds of deaths and culminating in the horrific St. Valentine’s Day Massacre in February 1929.