PITTSBURGH — The prosecution rested in the corruption trial of suspended state Supreme Court Justice Joan Orie Melvin and her aide and sister, Janine Orie, after an accountant testified Thursday that illegal campaign work allegedly done for Melvin by state-paid employees had cheated taxpayers out of more than $33,000.

The defense will begin calling witnesses today in hopes of rebutting claims by Allegheny County prosecutors that the sisters conspired to illegally use Melvin’s state-funded Superior Court offices and staff to campaign for the state’s highest court, and use the state-funded resources of a third sister, former state Sen. Jane Orie, for the same purpose.

The accountant, county Detective Jackelyn Weibel, testified that campaign work done by six staffers — four of Sen. Orie’s and two of Melvin’s — cheated taxpayers out of $33,476. She calculated that using the employees’ wages and their testimony about what percentage of working time they spent campaigning when Melvin lost a Supreme Court race in 2003 and in 2009, when she ran again and was elected.

Defense attorney Daniel Brier attempted to poke holes in Weibel’s testimony by asking how she corroborated that information. For example, Melvin staffer Kathy Squires testified she prepared campaign finance reports for Melvin, among other duties, but Weibel acknowledged Squires hadn’t signed those documents when the accountant reviewed them.

“You didn’t see, touch or feel any of those, did you?” Brier said, referring to any such documents signed by Squires.

“I did not,” Weibel said.

Similarly, Brier asked whether she double-checked the testimony of Lisa Sasinoski, a law clerk who testified Melvin fired her after she objected to doing campaign work in 2003. Sasinoski said she made several campaign stops at high-powered law firms with Melvin, but Weibel acknowledged she never called those firms to confirm such visits occurred.

The defense attorneys contend the campaign work wasn’t illegal because Melvin’s staff completed their assigned work, or that the campaigning amounted to too little to be a crime.

Common Pleas Judge Lester Nauhaus rejected defense motions to dismiss charges against Melvin, 56, and Janine Orie, 58, saying there was evidence of each crime in 10 days of prosecution testimony. By law, Nauhaus must take such testimony as true when deciding motions to dismiss.

Although the defense is seeking to minimize the conduct, the felony theft of services charge at the center of the case requires that prosecutors prove Melvin illegally used state-owned resources or property worth $2,000.

When Jane Orie, 51, was convicted last year of using her own state-funded staff for her own campaigns from 2001 to 2009, prosecutors calculated that work was worth $260,000.