Johnson slashed his throat with a makeshift blade fashioned from a small piece of metal attached to a wooden stick, said Michelle Lyons, spokeswoman for the Texas Department of Criminal Justice in Huntsville.
Prison guards had been checking on Johnson's welfare every 15 minutes, as is customary, when they found him unresponsive in a pool of blood in his cell, Lyons said. He was transported to a hospital in nearby Livingston, where he was pronounced dead, Lyons said.
There are some reports that he wrote on his cell in his own blood, "I didn't do it."
For information on Michael Johnson see http://www.adelante.com/michaeljohnson/index.html.