JEFFERSON CITY, Mo. — Missouri Gov. Eric Greitens may have gained an argument against impeachment when a St. Louis prosecutor dropped a criminal charge against him, but the governor's "great victory" seems to have done little to slow legislative momentum for an effort to try to remove him from office.

A day after the charge was dismissed, a House investigatory committee signaled that it's pushing forward with its own expanded investigation into allegations that extend beyond Greitens' acknowledged extramarital affair to his means of raising money for his 2016 gubernatorial campaign.

Republican legislative leaders affirmed that a monthlong special session focused solely on allegations against Greitens will convene Friday as scheduled. Attorneys for the governor's office are bracing for an impeachment defense, pre-emptively suggesting that lawmakers treat their hearings like a trial that allows them to call and question witnesses.

"What we do in a special session is totally divorced from what happens in a criminal case in St. Louis city," said Rep. Kathie Conway, a Republican who was among the first to call on Greitens to resign after his affair became public. "I don't think it's as good of news for the governor as he might want everybody to think."

Greitens, 44, was charged with felony invasion of privacy for allegedly taking and transmitting a photo of an at least partially nude woman without her permission in March 2015, before he was elected governor. Greitens hasn't directly answered questions about whether he took the photo, but defense attorneys said prosecutors were unable to find such a photo on Greitens' cellphone or cloud storage as jury selection in the criminal trial got underway.

The Republican governor declared it a "great victory" when prosecutors dropped the charge Monday.

St. Louis Circuit Attorney Kim Gardner said she did so because a court said she had to answer questions under oath from Greitens' attorneys, who alleged that an investigator she hired had committed perjury and withheld evidence. Gardner's office says the criminal charge could be refiled by an assistant or special prosecutor.

A judge has yet to set a trial date on a remaining felony charge accusing Greitens of disclosing a donor list for The Mission Continues to his political fundraiser in 2015 without the permission of the St. Louis-based charity he founded.

The Missouri Constitution allows impeachment for a variety of reasons, including crimes, misconduct and "moral turpitude."

A felony conviction related to sexual misconduct would have almost assured Greitens' impeachment, said Dave Robertson, chair of the political science department at the University of Missouri-St. Louis.

A dropped charge leaves him "better off because he can claim some victory," Robertson said. "But it concentrates everybody's attention on what I think is a more serious and perilous process for the governor, which is the impeachment process."

The constitution doesn't require a criminal conviction for impeachment. If the House votes to impeach Greitens, the Senate then would appoint a judicial panel to preside over a trial on whether he should be removed from office.

"I still think that there is a significant amount of evidence and information and facts that were provided to the state representatives that would lead to an impeachment trial," said Sen. Denny Hoskins, a Republican who has clashed with Greitens.

Others who supported Greitens contend the dropped invasion-of-privacy charge should make it more difficult to get the 82 votes necessary to impeach Greitens.

"They better look very hard on that vote," said Sen. Dan Brown, a Republican who was one of just four senators not to sign a petition calling for the special session on disciplining the governor.

Republican Rep. Bryan Spencer, who initially signed and then removed his name for the petition, said he's heard from about two dozen people who believe "that with charges being dropped that the special session should be dissolved."

"It definitely sells his scenario and it makes it appear like it's political and a witch hunt," said Spencer, echoing a phrase Greitens has used to describe the investigations against him.

The House investigatory panel amped up its probe into Greitens on Tuesday. It decided to call Greitens' policy adviser Will Scharf as a witness and to subpoena information about a couple of obscure companies that contributed tens of thousands of dollars to Greitens' campaign.

The panel cited a memo Scharf wrote in July 2016, when he was working for Greitens' GOP primary rival Catherine Hanaway, suggesting that Greitens had used "shell companies to hide donors."

Greitens' attorneys, meanwhile, ratcheted up claims of misconduct by the prosecution team, making a complaint to St. Louis police alleging perjury by a private investigator hired by the circuit attorney's office. The police department said it would investigate.

Greitens' attorneys have suggested that any misconduct by prosecutors should also disqualify them from handling the separate computer data tampering charge related to the charity donor list.

Gardner spokeswoman Susan Ryan declined to discuss a timeline for that case and said the office has not decided whether to ask Attorney General Josh Hawley to take over the prosecution.