Two months later, a bomb was found outside of Reverend Giuliani's church, allegedly planted by Galleanists as retaliation for the incident at the rally.
The November trial of the eleven Bay View anarchists arrested for September's shooting incident was influenced by sentiment related to the bombing.
On Sunday, September 9, 1917, the Methodist minister of the Milwaukee Italian Evangelical Church, Augusto Giuliani, held a rally in support of America's war effort.
The rally was held in Bay View, a largely Italian neighborhood, near the Galleanists' Francisco Ferrer Circle clubhouse.
In Italy, he had baptized the son of Guglielmo Marconi before he had married an American missionary and joined her evangelization efforts in Bay View.
[1] As Giuliani finished his speech and the crowd sang "America", the Ferrer Circle's Galleanist anarchists mounted the platform and tore down the American flag.
The explosion killed ten detectives, including one who had been wounded at the September rally, and a bystander who had come to report a robbery.
Historian of anarchism Paul Avrich wrote that it might have been local Ferrer Circle anarchists, but it was more likely to have been two of the Galleanists from Mexico, Mario Buda with the assistance of Carlo Valdinoci, coming from Chicago and Youngstown, respectively.
The prosecution sought to prove conspiracy, similar to the Haymarket trial, that even if the defendants did not participate in the shooting, they were involved in the plan.
[8] The Bay View incident was the opening salvo in a series of attacks between police and the Galleanists across the United States.