The North Carolina political operative who oversaw a fraud-ridden voter-turnout effort on behalf of a Republican congressional candidate was arrested on Wednesday, a prosecutor said, after a grand jury accused him of a series of felonies.

The campaign contractor, L. McCrae Dowless Jr., was among five people charged in Wake County, North Carolina, in connection with misconduct related to absentee ballots. The prosecutions were a vigorous legal backlash against a rare instance of election fraud and cast a still-darkening shadow over North Carolina, where state regulators recently ordered a new election in the 9th Congressional District after finding that Dowless had orchestrated an illicit scheme for Mark Harris, the Republican candidate.

“These indictments should serve as a stern warning to anyone trying to defraud elections in North Carolina,” Kim Strach, the executive director of the North Carolina State Board of Elections, said in a statement.

The charges that were unsealed on Wednesday were not tied to the 2018 general election, which investigators are still examining and which Harris once appeared to have won by 905 votes. Instead, this week’s indictments were linked to an election in 2016, when Dowless worked for a different candidate, and the 2018 primary, when he was effectively on the Harris campaign’s payroll.

But the indictments describe many of the same activities that investigators believe played out last fall, when Harris was locked in a tight race with Dan McCready, the Democratic nominee. Dowless, for instance, was accused of directing his associates to harvest absentee ballots from voters and instructing workers to sign ballot envelopes as if they had been legitimate witnesses. North Carolina law typically forbids third parties from handling absentee ballots.

During parts of both the 2016 and 2018 elections, the indictments said, Dowless’ conduct “served to undermine the integrity of the absentee ballot process and the public’s confidence in the outcome of the electoral process.” According to the indictment, spoiled ballots were tabulated in both races, including the 2018 primary, when Harris defeated Rep. Robert M. Pittenger by 828 votes.

This article originally appeared in The New York Times.