Douglas L. Wright, 26, of Indianapolis; Brandon L. Baxter, 20, of Lakewood, Ohio; and Connor C. Stevens, 20, of Berea, Ohio, pleaded guilty to conspiracy to use a weapon of mass destruction, attempted use of a weapon of mass destruction and attempted use of an explosive device to destroy property used in interstate commerce, the U.S. Department of Justice said in a news release.
Anthony M. Hayne, 35, of Cleveland, had pleaded guilty in July to the same charges and agreed to cooperate with the prosecution.
Steven M. Dettelbach, U.S. attorney for the Northern District of Ohio, said Wright, Baxter and Stevens tried to detonate "what they thought were explosive devices they had planted" at the bridge in Cuyahoga Valley National Park.
The devices turned out to be fake bombs provided by an FBI undercover informant.
Stephen D. Anthony, special agent in charge of the Cleveland Division of the FBI, said the defendants admitted intent "to utilize violence, which threatened innocent citizens, to further their ideological views."
Court documents indicated Wright, Baxter, Hayne, Stevens and a fifth suspect, Joshua S. Stafford, are anarchists who formed a small group and initially planned to set off smoke grenades to divert law enforcement officials, allowing co-conspirators to "topple financial institution signs atop high-rise buildings in downtown Cleveland."
The plot subsequently included use of explosives, and the conspirators considered a number of targets in the Cleveland area before deciding to blow up the Route 82 Brecksville-Northfield High Level Bridge, which connects Brecksville, Ohio, to Sagamore Hills, Ohio, over the Cuyahoga Valley National Park.
Prosecutors said an undercover FBI employee monitored the plot closely and there was never any danger to the public.