HARRISBURG -- Attorney General Tom Corbett has "botched" the ongoing investigation into government corruption, his Democratic opponent in the November election said yesterday during a talk before the Pennsylvania Press Club.

He should have looked at all four legislative caucuses simultaneously, Northampton District Attorney John Morganelli said.

The initial focus on just one caucus -- House Democrats -- let the other three know the kind of information being sought and gave them a chance to destroy evidence, Mr. Morganelli said.

"If you wait around for 18 months ... and say 'I'll be back later for your evidence,' it's not going to be there," he said. "This investigation has been botched from the beginning."

Kevin Harley, spokesman for the attorney general's office, responded in a telephone interview yesterday afternoon.

"We executed a search warrant based on probable cause that evidence was being destroyed in the [House Democratic] Legislative Research Office. You need probable cause for a search warrant," he said.

He declined to say whether that action compromised the investigation, saying he cannot comment on an active case.

Brian Nutt, who took a leave of absence from Mr. Corbett's staff to manage his re-election campaign, also commented by phone.

"This is a delicate investigation. You don't just go in and grab evidence without probable cause," he said. "[Mr. Morganelli] doesn't know what has been obtained and what hasn't been obtained. He doesn't know what he's talking about."

Mr. Morganelli does know that Mr. Corbett has accepted campaign donations from lawmakers involved in the bonus investigation and from casino applicant Louis DeNaples, who has been charged with perjury. He said Mr. Corbett should recuse himself from the bonus investigation and appoint independent counsel.

"He's got a huge conflict of interest," Mr. Morganelli said.

Mr. Nutt said those donations occurred three or four years ago -- long before Mr. DeNaples applied for a casino license. During this election cycle, Mr. Corbett has not accepted donations from casino applicants, which would be illegal, or from any lawmaker in office between 2004 and 2007, the time period being scrutinized in the bonus investigation.

Past political donations have no bearing on Mr. Corbett's investigation of those who contributed to him, Mr. Nutt said.

"These are elected officials, and elected officials contribute to candidates of their party. That doesn't mean they're best friends or they go out to eat together every night," he said. "There is no conflict of interest."

A key component of the investigation has been a probe into whether millions of dollars in taxpayer money was illegally distributed in the form of bonuses to compensate people who worked on campaigns.

House Democrats spent the most on bonuses, $1.9 million in 2006 alone.

Mr. Morganelli said Senate Republicans have something to worry about as the investigation continues.

"There's a lot of evidence ... bonuses went to a lot of [Senate Republican staffers] who were not even working in Harrisburg during the time they were awarded. ... I don't know how you reward someone for work when they were not even working in Harrisburg; they were on leave working on campaigns."

Mr. Nutt said Mr. Morganelli has no inside information about the case and should not speculate on who the grand jury may or may not be focusing on.

Mr. Corbett is scheduled to be the keynote speaker at the next Press Club luncheon planned for next month at the Harrisburg Hilton.