On Halloween night in 2000, students trick-or-treating inside a girls’ dormitory at the Mississippi School for Mathematics and Science were suddenly interrupted by three boys in full Ku Klux Klan regalia. The three figures, wearing white hoods, robes and patches on their chests, strode menacingly through the hall.

“I just remember being petrified to the point of tears,” Victoria Brown, who is Black and witnessed the incident, told the Arkansas Times this week.

One member of that group, Brown told the Times, was Charles Beckham III — a man who, 20 years later, is now a Republican challenger trying to oust a conservative Democrat from the Arkansas state Senate.

After flatly denying the allegations from Brown and four other former classmates who spoke with the Times earlier this week, Beckham, 37, apologized on Thursday when the Arkansas Democrat-Gazette obtained and published court records showing that he was, in fact, booted out of school for wearing a KKK outfit.

“I do sincerely apologize for any angst or grievances that I have caused anyone as a minor, as that is not the man that I am today,” Beckham told the Democrat-Gazette. “I continue to unequivocally denounce the KKK and any like-minded hate groups and the rumors that I am or have ever been part of the KKK are absolutely ridiculous."

Beckham, who moved to Arkansas about five years ago and runs a propane distribution company, has a chance to unseat state Sen. Bruce Maloch, one of nine Democrats in the 35-member Senate, the Democrat-Gazette reported. While Maloch is a conservative Blue Dog Democrat, Beckham has sought to portray himself as more right-leaning on abortion and tax issues.

On Tuesday, the Times broke the allegations about Beckham’s school expulsion. The Little Rock alt-weekly spoke to five former classmates who described being “terrorized” by Beckham.

Speaking to the Democrat-Gazette, Beckham at first blasted those accusers and claimed the story was a partisan plot. “It is sad that the Democrats will do anything and say anything to try to win. The accusations that have been made about me are not only baseless and false, but disgusting,” he said.

But the Democrat-Gazette learned that Beckham’s family had filed a lawsuit over his expulsion, and documents from that case largely corroborate the classmate’s recollections.

The incident happened on Oct. 31, 2000, when Beckham — who went by “Bubba” at the time — was a senior at the Mississippi School for Mathematics and Science, a boarding school on a college campus, according to a summary of facts prepared by the Mississippi State Board of Education.

For an official school Halloween competition, Beckham wore camouflage pants and a white T-shirt covered in fake blood. But soon afterward, as students returned to their dorms to trick-or-treat, he and two classmates changed into KKK robes. Although the school board’s report describes the outfits as being sewn from bedsheets and pillowcases, classmates recalled them looking quite realistic.

“They weren’t sheets, they looked to me to be real robes,” Bronwen Haskel, a White classmate, told the Democrat-Gazette. “I remember seeing a Black classmate and the look of pain on his face.”

When Beckham and his cohorts marched into the girls’ dorm, the residents reacted with terror — in part because Beckham did not appear to be joking around. “He was serious,” Alana Nichols, another Black classmate, told the Times.

After Beckham was initially thrown out of the dorm by an administrator and suspended, school officials later expelled him. Although he argued that the costume was a joke made in “bad judgment,” the school board noted that the outfit so upset some classmates that they were shaking and crying. Ultimately, the board upheld his dismissal.

His family’s lawsuit was also dismissed in 2001, the Democrat-Gazette reported, and Beckham finished high school in his hometown of Pascagoula, Miss.

Former classmates have flooded the Beckham campaign’s Facebook page with messages about the incident, the Times reported, urging voters in Arkansas not to send him to the state Senate.

“When I think about people who would do good as a public servant, he is close to the last person on that list,” Eric Seymour, a White classmate of Beckham’s, told the Times.