"Mr. Matthews is delighted with the result and looking forward to his future," said his attorney, Matthew Haverstick.
Matthews, 62, did not return calls Tuesday for comment. But in a letter sent to the District Attorney's Office on Tuesday, he wrote that he accepted responsibility and apologized for his actions.
"Citizens expect their public officials to be truthful and honest, to do otherwise erodes the foundations of government," the letter read. "I fully support the time and effort that the grand jury devoted to their investigation."
County detectives arrested the then-commissioner in December after an 18-month grand jury investigation into allegations that he misused campaign contributions, shepherded government contracts to friends, and conducted county business in secret.
In a 69-page report, the panel concluded that while many of Matthews' actions during his years at the helm of government had been unethical, they did not rise to the level of crimes.
He was charged, however, with lying during his grand jury testimony about a past relationship with a company that had been awarded county contracts and about discussions he had with witnesses in the case against him.
In March, a judge threw out one count of felony perjury against him, but held the misdemeanor false-swearing count for trial.
Matthews described the case as a political witch hunt.
In addition to the criminal charges, the grand jury offered a number of recommendations to improve the way the county awards its contracts, hires government employees, and conducts its business in public.
A new administration - led by Democratic Commissioners Chairman Josh Shapiro - has instituted many of those changes since taking office in January.
"Our primary goal in this investigation was to expose and eradicate government practices that served the interests of the elected officials and not those they served," District Attorney Risa Vetri Ferman said in a statement Tuesday. "I am satisfied that we have accomplished this goal and the best interests of our community are served by concluding this matter."
Contact Jeremy Roebuck at 267-564-5218 or firstname.lastname@example.org, or follow on Twitter @jeremyrroebuck.