A Florida man being held in the Washington County, Tennessee Detention Center is the third inmate to die at the facility in recent months.
The sheriff's department says 29-year-old Aaron Michael Bever died Monday night of a self inflicted injury. Bever had been arrested by Johnson City Police on June 14 on charges of being a convicted felon in possession of a handgun.
The investigation has been turned over to the TBI.
The TBI is also still investigating two more inmate deaths from the facility from earlier this year.
A sheriff's department spokeswoman says they are still waiting on autopsy results in those investigations, but they do not appear suspicious.