The police began rounding up suspects the following day beginning with the staff of the Arbeiter-Zeitung, an anarchist newspaper. News of the arrests spread throughout the anarchist community as more radials were taken into custody including people who had not even been present in the Square when the bomb was thrown. Police raided all radical groups without warrants and arrested 200 people and held them without counsel. Of all the people taken into custody, ten were indicted by the Grand Jury on May 27, 1886, and charged with the murder of Officer Matthias Degan who had been killed when the bomb exploded. The men were also charged with conspiracy, riot, and unlawful assembly. William Seliger decided to turn state's evidence and was not tried, and Rudolph Schnaubelt, the man many believed to have thrown the bomb, disappeared before the trial.
The eight defendants were:
Albert Parsons- the only American born anarchist, he had spoken at the rally but had left before the bomb exploded along with his family and went to Zepf’s hall, a saloon. At the urging of his wife Lucy he had fled Chicago, but returned to stand trial with his comrades.
August Spies -the editor of the Arbeiter-Zeitung, Spies had been present at the McCormick Riot and spoke at the Haymarket Square. He was on the speaker wagon when the bomb exploded.
Michael Schwab- assistant editor of the Arbeiter-Zeitung, had left Haymarket Square before the meeting took place and was speaking at another meeting when the rally and bombing took place.
Samuel Fielden- It was his speech urging workers to “throttle the law” which caused the police to intervene in the Haymarket.
George Engel- He had not attended the rally, but was a member of the Norhwest Side anarchists who planned it, and were accused of forming a conspiracy.
Adolph Fischer- Also a member of the Northwest Side group, it was Fischer who added the phrase “Working men, arm yourselves” on the original Revenge Circular which were removed at Spies request. He left the rally before the bomb was thrown and went to Zepf’s Hall, a saloon.
Oscar Neebe- assistant manager of the Arbeiter-Zeitung, he had not attended the rally but was arrested for possessing fliers advertising the rally.
Louis Lingg- had not attended the rally, but was manufacturing bombs with William Seliger. The bombs were picked up, and the two men went to a saloon.
 Paul Avrich, The Haymarket Tragedy, (Princeton, NJ: Princeton University Press, 1984), 224.
 James Green, Death in the Haymarket: A Story of Chicago, the First Labor Movement and the Bombing that Divided Gilded Age America, (New York: Pantheon Books, 2006), 185.
Picture: Dave Roediger and James Rosemont, Haymarket Scrapbook, (Chicago: Charles H. Kerr Publishing Company, 1986), 2.