Matthew Michanowicz, 53, pleaded guilty to one count of of violating federal firearms law Monday.
Michanowicz admitted that, on or about May 31, 2020, he placed three unregistered homemade destructive devices in a camouflage backpack at PNC Plaza.
The law provides for a maximum penalty of 10 years in prison, a fine of $250,000, or both.
The Bureau of Alcohol, Tobacco, Firearms and Explosives, Federal Bureau of Investigation, Pittsburgh Bureau of Police and the Allegheny County Sheriff’s Office conducted the investigation that led to the prosecution of Michanowicz.
Sentencing is scheduled to take place on Dec. 13.