ST. LOUIS — The trial was to be a major test for Gov. Eric Greitens of Missouri, a former Navy SEAL once lauded as a rising star in the Republican Party and, perhaps someday, a contender for president.
Prosecutors said that, in 2015, Mr. Greitens had taken an explicit photo of his former hairdresser without her consent. For months, the accusation had dogged his young governorship and upended politics across Missouri.
Then on Monday, with a trial set to begin this week and jury selection already well underway, Mr. Greitens watched from a St. Louis courtroom as the case suddenly collapsed. Prosecutors abruptly announced that they were dropping their felony invasion-of-privacy charge against him.
For Mr. Greitens, who has for weeks proclaimed his innocence and fought off demands that he resign, the announcement was a significant win. “This is a great victory, and it has been a long time coming,” Mr. Greitens, 44, said outside the courthouse, where he spoke briefly but did not answer questions. “This experience has been humbling, and I have emerged from it a changed man.”
Still, Mr. Greitens, only a year and a half into his first term in office, remains entangled in a legal and political thicket, and his future remains very much in doubt. A second felony charge, of tampering with computer data, awaits; prosecutors contend that he illegally obtained a donor list from a veterans’ charity he founded and used it for his 2016 campaign. And he faces a looming threat to his governorship from the Missouri General Assembly, which has scheduled a special session on Friday that could lead to a vote on impeachment.
In dropping the invasion-of-privacy charge, prosecutors cited the defense team’s decision to call the St. Louis circuit attorney, Kimberly Gardner, as a witness in the case. The lawyers for Mr. Greitens had accused Ms. Gardner of condoning misconduct and lying by an investigator on the case, and apparently intended to question her on those issues.
“When the court and the defense team put the state in the impossible position of choosing between her professional obligations and the pursuit of justice, the circuit attorney will always choose the pursuit of justice,” said Susan C. Ryan, a spokeswoman for the prosecutor, in a statement explaining the decision to drop the charge. “The court’s order leaves the circuit attorney no adequate means of proceeding with this trial.”
But the case had other troubles from the start.
Ms. Gardner, a Democrat, filed the felony charge in February, accusing Mr. Greitens of taking the explicit photo of his former hairdresser, with whom he has acknowledged having an affair. The woman, who has not been identified, was captured on a secretly recorded tape telling her then-husband that Mr. Greitens had blindfolded her, torn off her shirt and pants and taken a photo without her consent. Her ex-husband released the audio recording of the conversation to the news media over her objections.
Months after bringing the charge against Mr. Greitens, prosecutors still had not obtained such a photo, despite searches of the governor’s cellphone and electronic cloud accounts. The woman at the center of the case was a reluctant witness as well, declining all media interviews and pleading for privacy.
And the case had more challenges: The judge disqualified some of the prosecution’s expert witnesses. The charge itself is seldom used and difficult to prove without a photo. Even the process of jury selection had been dogged by delays. Three days in, jurors had still not been picked and lawyers had sparred over whether an unbiased group could be selected.
Late Monday, the St. Louis Circuit attorney’s office said it would now seek a special prosecutor, and that the case against the governor could be refiled at some point. But Anders Walker, a law professor at St. Louis University, said he would be surprised if a similar charge was brought again.
“I think the circuit attorney sat down over lunch, decided that since no photograph was found in discovery, that this case was over,” Mr. Walker said.
State Senator Jamilah Nasheed, a Democrat from St. Louis, said she believed Ms. Gardner made the right call by dropping the charge. “I’ve always thought that the case was weak,” Ms. Nasheed said.
But Ms. Nasheed cautioned against seeing Monday as a victory for the governor, who she said is in more peril from the other criminal charge against him and the looming threat of impeachment.
For Mr. Greitens, the threat of impeachment is real. The Missouri Legislature is dominated by Republicans, but Mr. Greitens is not a popular figure even in his own party. (A former Democrat, he switched parties to run for governor, announcing in 2015 that he no longer believed in liberal ideas.)
“The governor has lost the moral authority and the ability to lead the state going forward, and we reaffirm our call that he resign immediately,” Republican leaders in the State Senate said in a statement on Monday.
State Representative Gina Mitten, a Democratic member on the House committee investigating Mr. Greitens, said in an interview that the dismissal of the charge “doesn’t change a thing.”
“We are an independent body,” she said. “Our committee has conducted an investigation for more than two months, and personally I do not think that the developments in the criminal case should have any impact on our committee continuing to investigate all allegations against the governor.”
The committee has issued two reports on Mr. Greitens so far.
Throughout the process, Mr. Greitens has sat in the courtroom surrounded by his lawyers, watching intently as prospective jurors commented on his campaign for governor, his performance in office, the wall-to-wall news coverage of the case and their conversations with co-workers and neighbors about the felony charge before him.
Outside the courthouse, lawyers for Mr. Greitens reiterated claims of malfeasance by Ms. Gardner’s office and called for the other felony case against the governor to be dropped.
“It was misconduct from the beginning of this case to the end,” said Scott Rosenblum, one of the governor’s lawyers.