Dr. Kris Sperry, who quit as Georgia's chief medical examiner after an investigative report in The Atlanta Journal-Constitution, was warned six years ago about moonlighting from his state job, Atlanta television station WAGA reported Tuesday.

In a 2009 story, the station said Sperry sometimes hired himself out as an expert witness for criminal defendants in other states. One of those defendants was the accused killer of a Tennessee police officer. As an employee of the Georgia Bureau of Investigation, Sperry was barred from testifying in opposition to other law-enforcement agencies.

In June 2015, state medical examiner Kris Sperry testifies that Theresa Parker's jawbone showed signs of blunt force trauma during Sam Parker's motion for a new trial hearing in Judge Jon "Bo" Wood's courtroom at Walker County Superior Court in Lafayette, Ga. Parker was convicted of killing his dispatcher wife, Theresa, in 2009, but her body wasn't found until 2010.

Credit: Alan Judd

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Credit: Alan Judd

After that 2009 story, "I told him to follow the agency policy and not deviate from that," GBI Director Vernon Keenan told WAGA reporter Dale Russell this week.

The Journal-Constitution reported earlier this month that Sperry took on more than 500 cases as a paid expert witness between 2003 and 2014 – work that frequently took him out of the office, created conflicts of interest and exposed him to questions about his credibility.

On 67 days since 2010, the newspaper reported, Sperry filed time sheets claiming he worked eight or more hours at the GBI when he spent at least part of the day on his outside business.

On 13 of those days, Sperry actually was out of the state, testifying for private clients.

Although he was paid about $184,000 a year, Sperry was considered an hourly employee and was required to submit weekly time sheets. False statements on those documents can lead to criminal charges, with a penalty of one to five years in prison. After the Journal-Constitution's inquiry, Keenan deducted about 5 ½ weeks from Sperry's accrued vacation and other leave time, worth about $20,000. Keenan told the newspaper last week he had asked the attorney general's office to review the discrepancies in Sperry's time sheets.

Since the 2009 television report, Sperry apparently has not represented criminal defendants, according to the Journal-Constitution’s review of court records and other documents.

But testifying only for the prosecution in criminal cases presents ethical issues for medical examiners.

A 2009 report published by the National Academy of Sciences said a medical examiner should avoid being seen as "a servant of law enforcement." Medical examiners, the report said, often much examine sensitive cases involving shootings by police officers or deaths in custody. Those cases "require an unbiased death investigation that is clearly independent of law enforcement."

As Dr. Cyril Wecht, the longtime medical examiner in Pittsburgh, said in an interview: “How can you say you have no bias if you only testify for one side or the other?”