Two labor leaders, Thomas Mooney and Warren Billings, were convicted in separate trials and sentenced to death, later commuted to life in prison.

The Chamber of Commerce organized a Law and Order Committee, despite the diminishing influence and political clout of local trade unions.

An unsigned anti-war pamphlet issued throughout the city in mid-July read in part, "We are going to use a little direct action on the 22nd to show that militarism can't be forced on us and our children without a violent protest.

After the Preparedness Day bombing, Berkman abruptly abandoned The Blast and returned to New York, rejoining Emma Goldman to work on the Mother Earth Bulletin.

[10] The conservative leaders of local unions and editors of labor trade papers disliked Mooney intensely, believing him to be a "dangerous troublemaker" whose methods "never produced anything but trouble.

After the grand jury returned an indictment, Mooney and his wife Rena, Warren Billings, Israel Weinberg, and Ed Nolan were charged with murder.

Mooney and Billings eventually retained a well-known San Francisco criminal attorney, Maxwell McNutt, as their defense counsel.

[2] Two years later, a Mediation Commission set up by President Woodrow Wilson found no clear evidence of Mooney's guilt, and his death sentence was commuted.

The Mooney case and campaigns to free him became an international cause celebre for two decades, with a substantial literature of publications demonstrating the falsity of the conviction.

In addition to the language of the unsigned July warning leaflet, the Preparedness Day Parade had been organized by the Chamber of Commerce and the anti-union conservative business establishment to inspire patriotism and support for U.S. entry into the war, a development that could hardly fail to infuriate anarchists.

Buda, who was a bomb-maker of deadly repute, fit at least one witness's physical description of the bomber,[11][12] and the Galleanists were known to utilize time bombs consisting of cast steel or iron pipes packed with dynamite and metal slugs or other types of shrapnel to increase maiming and overall casualties.

[13][14] While the Galleanists conducted most of their bomb attacks on the East Coast, there was a large and restive Italian anarchist community in San Francisco at the time, and many of them subscribed to Galleani's journal, Cronaca Sovversiva (Subversive Chronicle), which openly called for direct action via propaganda of the deed while glorifying the assassination of "militarists" and "capitalists".

[8] Additionally, in an apparent oblique reference to an event in February 1916 in which a Galleanist operative in Chicago, Nestor Dondoglio, served poisoned soup to a host of political, religious, and business leaders, San Francisco police recovered two unsigned letters urging the headwaiter at the St. Francis Hotel to serve poisoned soup to Police Commissioner James Woods, one of the organizers of the Preparedness Day march, when Woods next came to dine there.

[23] On March 6, 1927, Eklund and another man known only as "Ricca" were shot by police as they attempted to light the fuse of a large dynamite bomb in front of the Saints Peter and Paul Catholic Church in San Francisco.