A high-profile investigator for the Richmond County Sheriff's Office was demoted Monday and placed on probation after an investigation determined he left behind case files and SWAT gear when he moved out of an apartment earlier this year.

Richard Roundtree, a sergeant in the Criminal Investigative Division who just returned to duty after extended training at the FBI Academy in Quantico, Va., was stripped of his rank and forced to leave the violent crimes division after a review board hearing, Maj. Ken Autry said.

The case files, which included five open "cold case" homicide investigations and two closed ones from 1988 to 2003, were left by Investigator Roundtree after he moved out of a Telfair Street residence earlier this year. The files were discovered by its new owners in July. They also found a .22-caliber rifle, which was a personal firearm, Maj. Autry said.

Investigator Roundtree also was cited for a number of Sheriff's Office policy violations and also faces five days of unpaid suspension and 12 months of probation.

"These files, the fact that they were left there, was just totally unacceptable," said Maj. Autry, who supervises the Criminal Investigation Division.

Officials refused a request by The Augusta Chronicle to reveal the names of the cold case files, which had been unsecured in the uninhabited residence for about six months.

But one of two closed cases involved the shooting death of 57-year-old grandmother Margaret Ann King, who was killed during a robbery in 2003 at the Central Avenue gas station where she worked. The other involved the fatal shooting of Chris Michael Price in 1996.

Maj. Autry said an investigation conducted by Investigator Roundtree's supervisors, determined no cases were immediately affected by the missing case files.

The investigation also scrutinized allegations that Investigator Roundtree had inappropriate contact with a female inmate during a criminal investigation after several letters written to him by the woman were found in his office. However, Maj. Autry said no wrongdoing was found.

Documents obtained last month by The Chronicle under the Georgia Open Records law show that Investigator Roundtree checked Charlene Thatcher out of the Richmond County jail on at least seven occasions between January 2002 to August 2003. She had been arrested in the 2001 kidnapping and murder of 16-year-old Samuel James Stirrup.

Sgt. Roundtree brought her from the jail to the Criminal Investigation Division on several occasions, including weekends, without escort. Officials admit that not all conversations between the two were documented. There is no account for the time, sometimes hours, that the two spent together in other instances.

Investigator Roundtree was the lead investigator in Mr. Stirrup's homicide, and Maj. Autry said it is not unusual for investigators to take inmates to the CID for interviews.

Investigator Roundtree also investigated Ms. Thatcher for having sexual relations with Deputy Jaime Felipe Banda, a jailer, who later faced sexual assault charges.

Ms. Thatcher, who is serving an 18-year sentence at the Metro State Prison for Women for armed robbery and aggravated assault, denied any improper relationship with the homicide investigator and no other people were interviewed, Maj. Autry said.

Staff Writer Sandy Hodson contributed to this article.

Reach Adam Folk at (706) 823-3339 or adam.folk@augustachronicle.com.