The service file shows that he enlisted at East Pass FL, Apr. 12, 1864, and deserted June 25, 1864. A pension application filed in his name in 1883 notes nothing definitive about him after he left the regiment, taking a blanket and pouch. The roll does note, "Killed by the Regulators in Coffee County Ala."
"Regulators" was a name applied to citizens protecting their homes and property. A negative term applied to the same kind of person is vigilantee.
This is not the same man as John M. Rhodes, Co. "H", 18th Alabama Regiment, who died in service. That man lived in Pike County, Ala. He could be the same man that enrolled in Co. "A", 6th Alabama Cavalry, a company recruited in and around Coffee County, Ala. If so, JMR would be a deserter from both sides.