Missouri Gov. Eric Greitens declared victory as prosecutors abruptly dropped a felony invasion-of-privacy charge alleging he had taken a revealing photo of a woman with whom he has acknowledged having an affair.

The St. Louis circuit attorney's office said it still plans to pursue the case, either through a special prosecutor or an appointed assistant. But Greitens' attorneys said the case was crumbling under a lack of evidence and doubted any charge would ever be refiled after Monday's dismissal.

The first-term Republican governor still faces plenty of other problems. Missouri's Republican legislative leaders renewed calls for Greitens to resign and confirmed they still will convene Friday in a monthlong special session to consider whether to impeach Greitens in an attempt to remove him from office.

Greitens also remains charged with a second felony in St. Louis for allegedly disclosing a donor list from a St. Louis-based veterans' charity he founded for use in his political campaign. No trial date has been set for that case.