The police assume that an anarchist had…
May 1886 CE
The police assume that an anarchist had thrown the bomb as part of a planned conspiracy; their problem is how to prove it.
On the morning of May 5, they raid the offices of the Arbeiter-Zeitung, arresting its editor August Spies, and his brother (who is not charged).
Also arrested are editorial assistant Michael Schwab and Adolph Fischer, a typesetter.
A search of the premises results in the discovery of the "Revenge Poster" and other evidence considered incriminating by the prosecution.