PITTSBURGH — A preliminary hearing has begun to determine whether state Sen. Jane Orie, R-40th, and her sister will stand trial on charges they illegally used Orie's legislative staff to do campaign work.

Part of Orie's district covers southern Butler County.

The Republican senator and her sister, Janine Orie, were charged in April after an Allegheny County grand jury determined they used the legislator's taxpayer-funded staff to do political work for her and a third sister, state Supreme Court Justice Joan Orie Melvin.

Melvin hasn't been charged and her sisters have denied wrongdoing. Janine Orie has been suspended with pay from her job as Melvin's aide.

The hearing is expected to last two or three days and will focus on testimony by the senator's staff and computer records kept by both sisters.