[1] Born and raised in North St. Louis to Irish-American parents, Harry and his brother John, known as "Pudgy", joined the Egan's Rats in their teens.

Locked up in the City Workhouse in the spring of 1913, Harry staged a daring escape and resumed his place in the Egan mob.

On December 21, 1915, Cherries Dunn got into a beef with a group of laborers in a saloon at Goodfellow and Cote Brilliante avenues and ended up fatally shooting John Groenwald over trivial reasons.

With a police dragnet out for him, Harry Dunn strode into Tom Egan's saloon at Broadway and Carr streets at 12:30 on the morning of January 8, 1916.

The final straw occurred on August 21, 1916, when Cherries Dunn and his pal, Eddie Schoenborn, shot and killed a semi-pro boxer named Harry Romani who was hooked up with the Egan mob.

During their conversation at the bar, two of Egan's men, Walter Costello and Frank "Gutter" Newman, shot and killed Dunn without warning.