The State Bureau of Investigation is probing campaign donations provided to North Carolina politicians by the video sweepstakes industry.
North Carolina Department of Justice spokeswoman Noelle Talley confirmed the criminal investigation into possible public corruption, which she said began in 2013.
North Carolina's attorney general is again seeking the power for prosecutors to call investigative grand juries for public corruption cases, saying the tool makes it easier to look into cases involving powerful people.
The grades are in for the year-long State Integrity investigation looking at the risk of corruption across the United States.
Several of the 50 states received an F. Not one scored an A. The Tar Heel State fell in the middle.
A former aide to ex-North Carolina Gov. Mike Easley must spend a year behind bars for failing to report a $30,000 profit on coastal property that was uncovered during a federal probe involving the two-term governor.