Jason Clark with the Texas Department of Criminal Justice said Friday that 62-year-old Mickey Patterson died in the infirmary at the Clements Unit in Amarillo. Patterson died Wednesday.
Patterson was convicted last year of murder in the August 2006 death of Kay Harrelson. He was also charged with killing another co-worker, Peggy Merimon, but wasn't tried in that case.
Harrelson's body was found in a ditch near Shallowater less than two weeks after the trio had lunch together and she disappeared.
Patterson was arrested in 2009 in Bend, Ore.
Merimon's remains were located in 2010 about 13 miles from where Harrelson's body was recovered.