PITTSBURGH — Prosecutors with the Allegheny County District Attorney's office opened their political corruption case against state Sen. Jane Orie on Monday at a preliminary hearing.

The state senator, a Republican who represents parts of Butler County in the 40th District, was charged in April with several counts of theft of services from the state after a six-month grand jury investigation recommended charges against her.

Those charges allege Orie and her sister Janine directed state-paid employees to engage in campaign-related tasks for herself and for a third sister, state Supreme Court Justice Joan Orie Melvin, who ran for that office in 2003 and was finally elected in another campaign in 2009.

Janine Orie at the time was an administrative assistant to Justice Melvin.

Prosecutors also allege Jane Orie forced more than 15 former staffers to stuff campaign envelopes, conduct campaign research, take campaign-related telephone calls and even drive Justice Melvin to campaign events.

Those charges allege Jane Orie and her sister directly violated state ethics rules because state employees are free to work on campaigns during their spare time but are forbidden to participate in campaign work while on the state's time.

John Contino, the executive director of the state's ethics commission, reinforced that idea as the first witness called to the stand Monday morning.

Contino, who's been with the commission for 25 years, said Orie voted to pass an ethics law as a state representative in 1998 and should know what is and is not a violation.

After Jane Orie's attorney, William Costopoulos of Harrisburg, said state ethics rules are murky and vague, Contino said he's sure Orie knew she was violating the law by directing staffers to work on campaign tasks while being paid by the state government.

"It doesn't take an extreme amount of knowledge (of ethics laws) to know when red flags arise," he said. "If you're in government long enough, you know when the red flags are there."

Prosecutors carted several large cardboard boxes of evidence into the courtroom of President Judge Donna Jo McDaniel on Monday before the proceedings began.

McDaniel will listen to the evidence during the preliminary hearing and make a decision whether enough evidence exists to send the case to trial.

Jane Orie came in with her sister and attorney but also was accompanied to the proceedings by her brother Jack and another sister, Judy, who sat in the gallery and watched the daylong hearing.

Deputy District Attorney Lawrence Claus called seven witnesses to testify against Jane Orie, including four former staffers who said Orie and her chief of staff, Jamie Pavlot, directed them to work on campaign-related tasks.

Those staffers allege the campaign work spanned almost a decade, lasting from 2001 up until last year.

Jason Davidek, a former Orie staffer for about two years who now works in the South Butler School District, said he drove Justice Orie Melvin to at least 20 campaign events while on state time.

Some of those trips included going to Philadelphia, Scranton and Reading in the eastern part of the state.

Davidek also said he most likely spent about 30 percent of his time at Orie's office performing campaign-related tasks, almost all of which were done while being paid by the state government.

Costopoulos countered and said Orie thought Davidek was being paid by her sister's campaign.

He also presented documentation that Davidek was compensated $300 for those trips and suggested he volunteered to take Justice Melvin on his own time, not the state's.

Sharon Cochran, Davidek's mother and also another staffer employed by Orie, said she too drove Justice Orie Melvin to campaign events, most notably to a dinner fundraiser in Johnstown.

Cochran said the trip took five hours and she was granted compensation time for her efforts, meaning the state technically paid her to make that trip.

Cochran also said she was sent out of the office several times during the day to canvass neighborhoods in the North Hills to solicit signatures or for other matters, and that Orie herself even came with her on at least one occasion for a door-knocking campaign.

During later testimony, former staffer Christa Meeder said there were some days where she spent more than 50 percent of her time on fundraising efforts for both Orie's and Melvin's campaigns.

Meeder said it was highly unlikely Orie was unaware her staffers were engaged in campaign-related tasks after questioning by Claus.

"It's unlikely because nothing was done in the office without the senator's knowledge," she said.

Costopoulos became heated in his cross-examinations of witnesses at times and grilled Detective Lyle Graber, the official with the county District Attorney's office who headed the investigation against Orie.

Costopoulos reiterated to the court that the entire investigation started when an intern from the University of Pittsburgh submitted a handwritten complaint to the district attorney's office last October alleging political corruption.

The attorney asked Graber why he asked for 18 search warrants "based on a complaint" from one intern who only worked for Orie for several months.

Graber responded the search warrants were executed only after interviewing several staff members, all of whom alleged a varying degree of political corruption was occurring in Orie's office.

"There was a common thread throughout the interviews that there was political campaigning consistently done with the senator's knowledge during their employment there," he said.

Senate clerk W. Russell Faber, under cross-examination, produced documents that showed Orie saved taxpayers $1,500 by passing up a cost of living increase one year and $7,700 by refusing a pay raise that was later rescinded in 2005. She also voted against a pension increase that will save taxpayers $9,000 a year once she retires, Faber said.

The preliminary hearing is expected to run through at least today before Judge McDaniel makes her ruling.

Jamie Pavlot, Orie's former chief of staff, is expected to testify today. She is immune from prosecution because of her cooperation in the case.

The Associated Press contributed to this report.