Texas plans to execute Marvin Wilson, who has been diagnosed as “mentally retarded,” on Tuesday. The 54-year-old man, who will be punished for his crimes by being put to death by lethal injection, does not meet the state’s definition of mental deficiency that would make the death penalty excessive punishment. Wilson was placed on death row after being found guilty of the murder of a police informant in Beaumont in 1992. Wilson was subjected to extensive psychological testing and was found at the time to possess the literacy level of a 7-year-old. He tested in the lowest IQ percentile of the population, managing a score of 61.