FILE - In this Jan. 29, 2018 file photo, Missouri Gov. Eric Greitens speaks in Palmyra, Mo. Missouri lawmakers are returning to the Statehouse for the first time Monday, Feb. 26, 2018 since Greitens was indicted, with plans to discuss assembling a committee whose investigation could lead to his impeachment. The first-term Republican governor was indicted late Thursday on felony invasion of privacy. (AP Photo/Jeff Roberson, File)

JEFFERSON CITY, Mo. - The St. Louis prosecutor's office said Tuesday that it has hired a Michigan firm to aid its investigation into Missouri Gov. Eric Greitens to try to ensure that the probe remains independent.

Documents filed in court show that St. Louis Circuit Attorney Kim Gardner hired Enterra LLC of Rochester Hills, Michigan, to help with an investigation of the Republican governor that was prompted by his recent acknowledgment of an extramarital affair in 2015.

A grand jury indicted Greitens on a felony charge of invasion of privacy Thursday. He's accused of taking a partially nude photo of the woman without her consent and transmitting it to a computer. Greitens has declined to publicly say whether he took the photo, but his attorneys have said he is innocent of the criminal charge.

A trial has been tentatively set for May 14. The investigation is continuing.

Greitens' attorney, Edward L. Dowd Jr., on Tuesday questioned why Gardner's office is using out-of-state investigators instead of local police and said that Greitens had hoped for an even sooner trial date to clear his name.

"The damage to this guy that's being done every day is absurd," Dowd said of Greitens.

Gardner spokeswoman Susan Ryan said the office first asked St. Louis police for help but was directed to the FBI, which in turn said the investigation was out of its jurisdiction.

"So we hired a company that had the expertise we were looking for and that also did not have any relationships in the state of Missouri, because we wanted this to remain as independent as possible," Ryan said.

Dowd said he obtained the circuit attorney's contract with Enterra through an open records request. The contract, which Dowd filed as a court exhibit, shows Enterra was to be paid a $10,000 retainer, with its employees paid at a rate of $250 an hour plus reimbursement for "reasonable expenses."

The agreement states that the investigative company would report directly to Gardner "either orally, or if requested, in written form."

Dowd, a former U.S. attorney who also worked on the Branch Davidian investigation in Waco, Texas, said he's never seen a situation in which a criminal case report was not in writing.

"It's more indication of how unusual this whole thing is," Dowd said.

Ryan said she didn't know how much money had been paid to the company so far. She also wasn't sure about the manner in which the firm submitted its findings.

Washington University law professor Peter Joy said hiring a private firm to help in an investigation is not uncommon when prosecutors are understaffed and under tight deadlines. In the Greitens investigation, the three-year statute of limitations for invasion of privacy would have expired in March.

"When you are kind of under the gun, hiring outside help would be something you'd do," Joy said.

He also said it's not unusual for prosecutors and defence attorneys to ask for oral reports and not written ones, but that it depends on the general practice of the office. He added that the case is moving "really quickly" for a felony punishable by at most four years in prison.

Gardner's office submitted a court filing Tuesday listing evidence it was supplying to Greitens' defence team, including a photo of the woman and emails between Greitens and the woman. Dowd said the photo was "a publicly posted professional headshot" — not the compromising photo the indictment alleges Greitens took.

Dowd, in court filings and in an interview, reiterated his belief that Missouri's invasion of privacy statute applies to voyeurs and not encounters involving consenting adults, even if the woman didn't know she was being photographed. She told her ex-husband in a conversation he secretly recorded that she was partially nude and blindfolded while in the basement of Greitens' home when he took the picture, threatening to use it as blackmail if she ever spoke of the affair.

"When you take your clothes off, you cannot expect not to be viewed in whatever place you're in, especially in somebody else's house," Dowd said.

The Missouri House also has formed a seven-member committee to investigate the allegations that led to Greitens' indictment. On Tuesday, committee chairman Rep. Jay Barnes filed a resolution outlining what the panel's work will involve.

The panel would be allowed to compel testimony and evidence using subpoenas. In some cases, information could be redacted to protect the identity of witnesses, the resolution says.

The committee also would be able to hire independent investigators, special counsel, court reporters and other personnel with House funds.

The panel would have 40 days to produce a report but could take longer. The committee could determine whether to recommend impeachment proceedings to try to remove Greitens from office.

___

Salter reported from St. Louis.

News from © The Associated Press, 2018