When editors of the Cavalier Daily discovered evidence of rampant plagiarism by a staff writer at the University of Virginia’s 121-year-old student newspaper last month, they dutifully reported it to their readers and removed the offending articles from the paper’s Web site.

They also contacted the university’s Honor Committee, made up of fellow students who enforce a tradition of academic integrity that is older, even, than the newspaper. At a campus as earnest as U-Va., it seemed the right thing to do.

But the editors soon found that they and the alleged plagiarist were pinned beneath the same wheels of justice.

Late Tuesday night, the month-long saga ended. The University Judiciary Committee — another student panel— cleared Jason Ally, editor in chief of the Cavalier Daily, of violating the university’s Standards of Conduct by publishing the Sept. 12 editorial that announced the journalistic sins.

Ally’s odyssey illustrates what can happen when the overheated rhetoric of student government yields real-life consequences. Self-­governance is a cardinal rule for the students of U-Va., an institution founded by Thomas Jefferson and infused with his distinctive vision of democracy.

Both the university’s Honor Committee and Judiciary Committee wield adult-size powers. At various times in recent weeks, Ally, four other Cavalier Daily editors and the alleged plagiarist all faced potential expulsion. The student accused of plagiarism has not been identified by the paper or the Honor Committee.

“I would like to think that the students of the University of Virginia are capable of governing themselves,” said Ally, a 21-year-old senior from Burke. “But the way this one situation played out does leave me puzzled.”

A copy editor at the Cavalier Daily discovered the alleged plagiarism in early September while fact-checking an article not yet published. The fact-checker searched for a passage on Google, and among the results was an article from a professional media outlet that included an identical passage. That triggered a broader review of the author’s work.

“It turned out that pretty much every single piece had been plagiarized,” said Andrew Seidman, a 21-year-old senior from Arlington County who is managing editor of the Cavalier Daily.

Passages had been copied verbatim from the New York Times, the Los Angeles Times and Wikipedia, among other sources, without attribution, the review found. The Cavalier Daily reported its findings in an article titled “Taking action” and credited to the publication’s five-person managing board.

Commercial newspapers are expected to identify plagiarists and even preserve their published articles, allowing the public to judge the situation.

The Cavalier Daily editors chose to conceal both the author and his work. The reason: They had reported him to the Honor Committee, a panel that goes to great lengths to protect the identities of alleged offenders. “We took every possible step to conceal the identity of the author,” Ally said.

The Honor Committee did not agree. A few days after the Cavalier Daily published its findings, the student chairman of the Honor Committee filed charges against all five members of the newspaper’s managing board with the Judiciary Committee.

The Honor Committee is a group of 27 students that enforces the university’s honor system, one of the strictest in academia. The panel tries students who are accused of lying, cheating or stealing, provided the alleged incidents are of sufficient gravity to “erode the community of trust.” There is but one penalty: expulsion.

The Judiciary Committee is a separate group of 23 students charged with upholding the university’s Standards of Conduct, a specific list of transgressions that range from blocking traffic to physical assault.

Ann Marie McKenzie, who chairs the Honor Committee, said she thought that the editors violated confidentiality rules when they wrote that they had “reported the incidents to the Honor Committee.” In essence, the students were accused of violating the sanctity of a confidential proceeding merely by acknowledging its existence.

McKenzie, a 22-year-old senior from Centreville, declined to comment on the case.

McKenzie eventually dropped the charges against all of the editors except Ally.

The prosecution of Ally brought howls of protest from faculty members and former Cavalier Daily staffers. First Amendment activists condemned it as overzealous enforcement of federal privacy rules, a common criticism of universities.

The Honor Committee’s rules are rooted in the Family Educational Rights and Privacy Act, a 1974 federal law that limits the release of student records.

But that law doesn’t apply to the Cavalier Daily or to any other student newspaper, said Adam Goldstein, an attorney advocate at the Student Press Law Center, a nonprofit organization in Arlington.

Furthermore, the constitution of the U-Va. Judiciary Committee states that the group has no jurisdiction over student journalism. That, in the end, was what the committee decided.

“What fundamentally happened here was that the student editor got called before a judiciary committee for exercising his First Amendment rights,” Goldstein said. “It’s fine to give students governance, but they need to keep them within the limits of the Constitution.”

The adults who run the university “did not take sides or issue an opinion” in the case, said spokeswoman Carol Wood. “But we watched closely as the students worked through their differences,” she said. “Many of us believe that this has been a great example of our students exercising their student self-governance and leadership muscles in the best of ways.”

Ally, after more than a month caught up in the university’s judicial system, said that the Cavalier Daily’s editors will work to “further clarify” the student newspaper’s independence from those proceedings.