Stephen Zappala Jr., district attorney in Allegheny County, will announce next week his campaign for state attorney general.

That could give rise to a lively Democratic primary election in April if the incumbent, beleaguered Attorney General Kathleen G. Kane, decides to seek a second term.

Kane is awaiting trial, accused of illegally leaking secret grand-jury information to the Philadelphia Daily News for a story.

Zappala has played a bit part in the ongoing drama around Kane: He testified as an expert witness for the Montgomery County grand jury that investigated her actions and recommended criminal charges against her.

Zappala, who did not respond to requests for comment from The Inquirer, confirmed his plans Wednesday evening, according to the Pittsburgh Post-Gazette.

A source close to Zappala, who has been district attorney since 1998, spread the word earlier in the day about the impending candidacy.

"He's running to restore confidence in the Attorney General's Office, which he believes has been eroded by the shenanigans of the incumbent," the source said.

Chuck Ardo, a spokesman for Kane, said it was not clear whether she will run for a second term.

"She has not made a final decision," he said. "But certainly the current circumstances would make it challenging for her to seek another term."

Ardo brushed off the talk of "shenanigans."

"As anyone who follows politics knows, candidates are apt to say almost anything, Mr. Zappala among them," Ardo said.

Word of Zappala's planned candidacy is surfacing just days before the state's political class decamps to New York for the annual Pennsylvania Society weekend - and is doubtless timed to start a conversation there about his run. Attendance at the posh political event, though, may be depressed this year by the continued wrangling in Harrisburg over passing a budget.

Zappala is likely to pitch himself as a prosecutor with experience in public corruption cases.

His office won corruption convictions against former state Supreme Court Justice Joan Orie Melvin and her sister, former State Sen. Jane Orie, both Republicans. They, along with a third sister, Janine, were accused of using office staffers on the state payroll for political work.

Zappala's father, Stephen Sr., served on the state Supreme Court for two decades and retired in 2002 as chief justice.

Notwithstanding the uncertainty over whether Kane will seek a second term, the list of candidates for her post is growing.

Democrat Jack Stollsteimer, a former county and federal prosecutor who lives in Delaware County, announced in August. David Fawcett, a former Republican member of the Allegheny County Council, told the Post-Gazette last month he would run as a Democrat.

Two Republicans from Montgomery County, State Rep. Todd Stephens of Horsham and State Sen. John Rafferty of Eagleville, have also announced their candidacies. Stephens is a former county prosecutor; Rafferty, a former deputy attorney general.

Josh Shapiro, chairman of Montgomery County's commissioners, and Northampton County District Attorney John Morganelli are also considering entering the Democratic primary. Shapiro is chairman of the state Commission on Crime and Delinquency. Morganelli ran for attorney general in 2008.