HARRISBURG -- More arrests are expected in an alleged scheme to pay bonuses to state employees for campaign work, a case in which 12 people already face charges, state Attorney General Tom Corbett said yesterday.

Mr. Corbett, who was re-elected Tuesday, said he couldn't say when additional arrests will be made or how much longer the corruption investigation, which began in February 2007, will take.

"I would expect some additional charges," he said. "Yes, I believe there will be charges."

He said the case is unpredictable because his investigators sometimes spend weeks chasing a lead that doesn't produce anything. Sometimes new information, like grand jury testimony or a computer or paper record, comes up suddenly.

Investigators are looking into whether taxpayer funds went for hefty bonuses for employees who did political work on state time in 2005 and 2006. The 12 charged so far are current or former House Democrats and staffers.

Mr. Corbett reiterated that all four legislative caucuses are being looked at, but the House Democrats spent the most on bonuses, $1.8 million in 2006 alone. Because his investigators got a tip that computer records were being destroyed in that caucus, it was investigated first.

During the campaign, his Democratic opponent, Northampton County District Attorney John Morganelli, claimed that Mr. Corbett was not aggressively investigating House and Senate Republicans, but Mr. Corbett said that isn't true.

Mr. Corbett was asked if he is pursuing recent court testimony from Mike Manzo, former chief of staff to House Democratic leader Bill DeWeese. Mr. Manzo, who has been charged in the case, testified at a hearing for another defendant that Mr. DeWeese knew about the bonuses being doled out illegally for political work.

Mr. DeWeese, who fired Mr. Manzo in late 2007, has denied doing anything wrong, and has not been charged.

"We are following up anything that any witness tells us," Mr. Corbett said. "I can't comment on the specifics of the investigation. We will try to corroborate and follow up any statement anybody makes in this investigation, but it takes time."

On another subject, Mr. Corbett didn't rule out running for governor in 2010.

"I enjoy public service," he said, noting he has been an assistant district attorney and U.S. attorney and served two tenures as state attorney general.

"I won't rule any [future political office] in or out right now. I just want to spend some time with my wife. I didn't see much of her in the last six months" because of the re-election campaign.

He also said he'll continue four initiatives begun in his first term: arresting Internet predators, adults who use the Internet to try to find minor children for sex; curbing gangs that bring illegal drugs into the state to sell; fighting elder abuse, including home remodeling and investment scams aimed at cheating senior citizens out of their savings; and the Philadelphia gun violence task force, in which the attorney general's office works with police and prosecutors to get illegal guns off the street.

He said other cities including Pittsburgh are interested in such a task force, but the Legislature would have to provide the money. So far, over the past three years, the state has provided $5 million a year for the gun violence task force in Philadelphia.