Randall Rustick, 33, had been charged with concealing a dangerous weapon and could have faced up to 10 years in prison if convicted. He was released Dec. 22 after signing a $10,000 signature bond.

Howard Luke, one of Rustick's lawyers, said the dismissal was filed by the U.S. Attorney's office in U.S. District Court today.

Luke said his client had no knowledge of how the blade got in his shoe. He said Rustick was "fully cooperative with our blessings" with the FBI and U.S. Attorney during their investigation.

Luke said it remains a mystery how the blade got into the shoe.

"We believe that it possibly could have been left there when the shoe was resoled, but I don't think ultimately we'll find the precise reason," Luke said. "But one thing is absolutely certain and that is that Randy Rustick did not know about it."

"He's elated. He's very, very happy," Luke said of Rustick, who is visiting his parents on Kaua'i with his wife and four children. "He was afraid that because of the nature of the incident and the presumption of guilt, that the truth might not come out. But thankfully it did."

Assistant U.S. Attorney Ken Sorenson, who was prosecuting the case, could not be reached for comment.