He faced the felony charge of invasion of privacy.
Greitens was accused previously of sexually assaulting and blackmailing a woman with whom he had an affair.
"I am disgusted, disheartened, and I believe Governor Greitens is unfit to lead our state," Wagner said.
The case against Greitens stems from his admission in January that he had an extramarital affair with his hairdresser.
"The serious allegations against Missouri Governor Eric Greitens are very troubling," the circuit attorney said on Thursday.
Missouri's Republican governor has apologized after a broadcast accused him of blackmail.
Stockley, a police officer, has been acquitted in St. Louis six years after he shot and killed Anthony Lamar Smith.
The police officer is being tried in the murder of Anthony Lamar Smith.
If passed, the legislation would also enable anti-abortion crisis pregnancy centers to operate without risk of political restriction.
Governor Eric Greitens has called a second extraordinary session in his first year in office to discuss stricter rules on abortion.