But the charge itself — invasion of privacy — is drawing intense scrutiny. Lawyers for the governor have asked a judge to dismiss it, saying it is being applied in a way lawmakers who wrote the statute never intended. And observers of the case and commentators in Missouri have dissected the language of the little-used statute in an effort to understand precisely what prosecutors are asserting that the governor did. Some were asking: Who else has been charged with this?

The law

Back in the 1990s, Jim Kreider’s constituents in southern Missouri were aghast when prosecutors said that they could not charge the tanning salon owner who was thought to have recorded dozens of naked women. So Mr. Kreider, a Democratic state representative, sponsored a bill that made invasion of privacy a felony.

“It got a lot of press and it got a lot of coverage and letters to the editor, and people were pretty outraged about it,” Mr. Kreider, now a lobbyist in the state capital, said of the tanning salon case. Of the bill, he said, “it passed with relative ease.”

The law makes it a felony to knowingly photograph or film a nude person without consent in a place where they would reasonably expect privacy, and to then distribute that recording or transmit it so it could be seen on a computer.

The law was too late for the tanning salon case from Buffalo, though. Prosecutors found a different route to charge the salon owner. He was accused and convicted of child abuse when it was revealed that some of the people he filmed were minors.