NBC Augusta is learning more about the personnel history of a violent crimes investigator with the Richmond County Sheriff’s Office.

Sgt. Richard Roundtree will go before a review board in September for possible disciplinary action.

Roundtree is accused of misplacing five case files. Sources tell NBC Augusta the case files were recently found in an apartment Roundtree used to live in.

NBC Augusta obtained a copy of his personnel file and found this isn't the first time he's faced disciplinary action.

In September 2004, Roundtree received a written warning for misplacing a recorded interview of a witness in a homicide investigation. That tape was later found on his desk.

A few months later, he was warned again for a case file that was unorganized and incomplete.

In September 2005, Roundtree was suspended for two days after he lost another recorded interview with a witness of a 1994 unsolved homicide case. That lost tape, along with unreliable witnesses and other missing evidence lost prior to Roundtree taking the case led to the suspect being acquitted.

Surveillance video from 2003 shows Margaret King pleading for her life during an armed robbery at the Pump 'N Stop on Central Avenue in Augusta.

Cedric Beals was charged and convicted in King's killing. In a plea deal, Beals received two life prison sentences.

Originally the District Attorney's Office sought the death penalty. The District Attorney's office tells NBC Augusta, when they were preparing for Beals' trial, they were told by the sheriff's office the original case file was lost. Five years later, that original case file and four others were found in Roundtree's former apartment.

Typically, the state needs the original case file in order to pursue the death penalty. But the DA's office tells us that was NOT the reason the plea deal was made. They say there was a lack of positive identification of Beals.

Also in Roundtree's file, ten thank you letters from people in the community commending him for solving cases and protecting neighborhoods and 22 certificates of achievement.

Roundtree's been with the department for 15 years and has helped solve dozens of violent crimes.