Treasury investigators tracked the phone calls back to a phone account associated with Johnson, according to the indictment. When Treasury agents investigated the threat in the weeks after the call, Johnson told them two other men were responsible.
Johnson told the investigators on April 16 that an individual identified by the initials D.C. borrowed his cell phone and made the calls. Four days later, investigators had cleared the individual, so Johnson offered up anther individual identified as R.S., who investigators also cleared. Then in October he admitted he made the threat himself.
Johnson, charged with threatening the use of explosives on a building as well as two counts of making a false statement to federal agents, faces a maximum penalty of 10 years in prison on each count if convicted and a potential fine of $250,000.