Jurors heard Friday how an intern's concerns about campaign activity on public time sowed the seeds of the charges that now threaten the political career of one of the state's most powerful lawmakers.

Jennifer Rioja was a graduate student at the University of Pittsburgh, pursuing master's degrees in social work and public affairs, when she secured an unpaid internship with the Republican's North Hills office. She said she performed at least one minor political chore herself, without complaint, and observed campaign work by other staffers in the North Hills office. In October 2009, she decided to leave her internship and report the campaign activity to law enforcement officials after hearing that a fellow intern had been recruited to help prepare a political mailing for the senator's sister, Judge Joan Orie Melvin, to convents across the region.

In a vivid cross-examination, a defense attorney tried to suggest that Ms. Rioja's complaint to the district attorney's office, days before the November election, was the product of a partisan agenda.

"Did you blog on Senate computers the fact that you were a Communist?" William Costopoulos, Ms. Orie's attorney, demanded as he tried to dent Ms. Rioja's credibility.

"Did you blog the fact that you were a Commie liberal for many years?" he asked moments later.

Ms. Rioja, who appeared unperturbed by the defense scrutiny, acknowledged that she had referred to herself as a "Commie liberal" in a comment posted in a discussion on Jezebel, a national website focused on issues of concern to women. While she described herself as a registered Democrat with liberal views, she insisted that she had no political motive either in her pursuit of the Orie internship or her eventual decision to report the office activities she found improper.

She noted that she had applied to politicians of both parties in seeking the internship needed to fulfill her academic requirements.

She said she did not hide political views and suggested that they had never been a problem in her interactions with fellow staffers in the GOP office.

"Jamie [Pavlot, Ms. Orie's chief of staff] joked about me being the office's little Democrat," she recalled.

The defense's discovery and exploitation of the Jezebel comment was one more example of the digital archaeology that has run through the trial. Much of the prosecution's case over the seven days of testimony has been buttressed with displays of e-mails and archived political documents, some nearly a decade old, downloaded from the files of the Senate computers in Orie's offices.

Ms. Rioja said her first encounter with campaign activity in the office came when she was asked to place fliers for Justice Melvin's 2009 high court candidacy on a table next to a display of legislative materials as she staffed an Orie booth at a summer fair at St. Alexis parish in the North Hills. Through the summer and fall, she said she became increasingly aware of political activity by other staffers in the McKnight Road office.

She said she finally decided to resign from the office, and then to go to prosecutors, in the last days of October. She said she first reported her concerns to faculty advisers. As she recounted the seminal events of Friday, Oct. 30, she went to the Orie office before normal working hours and resigned after a brief conversation with Ms. Pavlot.

Then she went home and made the first of a series of attempts to press a formal complaint. She tried to contact the bureau of elections in Harrisburg but was frustrated by an automated phone tree that failed to connect her with a human being. Then, she called the state attorney general's office, which, by then was well into a heavily publicized investigation of legislative corruption in Harrisburg.

Without using Ms. Orie's name, she attempted to lodge a complaint there, but was told that she should pursue the issue with her local district attorney. She did, and by about 10:30 that morning she was in the Dormont offices of the DA's investigations unit filling out the complaint that led to this trial.

Apprised of the accusation in early November, Sen. Orie sent Ms. Rioja a letter, with copies to her graduate school advisers, calling her charges, "baseless, slanderous and defamatory."

"At no time has any member of my staff engaged in any political activity during, or on official state working time," she wrote.

Under cross-examination, Ms. Rioja acknowledged that she did not know whether some of the political activity she'd seen might have taken place on comp time.

But in his final questions, prosecutor Lawrence Claus prompted the witness to recall previous testimony in the investigation in which she had reported that on one social occasion a fellow staffer had said that if prosecutors knew what they were doing on state time, "they would be led out of the office in handcuffs."