Tennessee inmate David Earl Miller has been moved to death watch before his scheduled execution on Thursday.
The Tennessee Department of Correction said Tuesday that Miller was moved shortly after midnight.
Death watch is a three-day period in which strict guidelines are implemented to maintain security and control. During this time, Miller will remain in a cell adjacent to the execution chamber where he will be under 24-hour observation by a team of correctional officers.
Miller has asked the U.S. Supreme Court to halt the execution and consider his claims that the electric chair is unconstitutional but the state's lethal injection method is worse.
His attorneys filed a petition with the high court Monday after a panel of the 6th U.S. Circuit Court of Appeals ruled against the inmate.
Miller has chosen to die by electrocution, the second Tennessee inmate in just more than a month to make that choice. His attorneys have argued that Tennessee's preferred execution method of midazolam-based lethal injection cause a prolonged and torturous death.
The 6th Circuit ruled that Miller could not challenge electrocution because he chose that method. His attorneys argue the choice was coerced by the threat of something even worse.