State prosecutors added more defendants Tuesday to their expanding legislative corruption case, accusing a longtime House Democratic leader and a former legislator serving in the governor's cabinet of illegally using taxpayer-paid employees to perform campaign work.

State Rep. Bill DeWeese, the former House speaker, and former Rep. Stephen Stetler, who resigned as Pennsylvania's secretary of revenue hours before the charges were announced, face four counts of theft and one count each of conspiracy and conflict of interest. A district office aide to DeWeese, Sharon Rodavich, also was charged.

Attorney General Tom Corbett's investigation has focused on the blurring of the lines between political work and legislative jobs in the Capitol, and he said Tuesday that some state lawmakers have been slow to get the message.

"The evidence here is clear that they were using public resources for political purposes," he said. "That's illegal. It's a conflict of interest, common sense will tell you."

DeWeese is the second former House speaker ensnared in the probe; former speaker John M. Perzel of Philadelphia is among 10 people with ties to House Republicans who have been charged. Corbett also has charged 12 other people associated with the Democratic caucus in the three-year-long investigation.

With the latest filings, 25 people connected to the House of Representatives have been charged.

On Tuesday night, DeWeese took the microphone after a late House floor vote to say he was resigning his current leadership post as House Democratic whip and to thank his well-wishing colleagues.

"I've had a tough day ... but I want to say to one and all that I've enjoyed being the Democratic whip and God only knows what will be forthcoming on the future," he said before receiving a standing ovation.

Earlier Tuesday, DeWeese issued a written statement saying he had cooperated with Corbett's investigation and worked "to change the culture of the caucus by implementing ethics training and whistle-blower provisions. Obviously I'm disappointed by today's action."

Stetler is a former campaign strategist for the House Democrats who left the Legislature in 2006. Messages left at his home and at the office of his lawyer, Josh Lock, were not returned.

It was unclear whether Rodavich had a lawyer, and a phone message left at her Carmichaels home was not returned.

According to Corbett, DeWeese allegedly employed a legislative staff member in the Capitol from 2001 to 2007 primarily to raise campaign money. Kevin Sidella testified under a grant of immunity that he raised millions of dollars for DeWeese's political campaigns while being paid by taxpayers, Corbett said.