Experts don't know exactly how many people with mental retardation are on death rows across the country. But based on the IQs of those who've been executed, officials estimate that 10percent of the 3,600 Americans now on death rows are retarded - more than triple the 2percent to 3percent in the general population. The Center for Death Penalty Litigation in Durham, a nonprofit organization that assists attorneys in representing people in capital cases and which takes no stand on the death penalty, says records show that at least 25 of the 213 inmates on North Carolina's death row have IQs of 75 or lower. And at least three other inmates with IQs that low were sentenced to death and are awaiting new trials. In South Carolina, death penalty lawyers say five to 10 of the state's 68 death row inmates are retarded.
Mental retardation is caused in hundreds of ways.
Malnutrition and other effects of poverty, childhood injuries, lead poisoning, chromosomal disorders such as Down syndrome, alcohol and drug use by mothers during pregnancy and childhood diseases are just a few of the reasons why about 7million people in the United States have mental retardation. It is different from mental illness, although people with mental retardation are more likely to have a mental illness. While its effects vary, it does not make a person more or less violent or prone to committing crimes. Mild retardation can cause serious difficulties in understanding and the ability to function. And because it is mild in more than 85percent of the cases, it is, unlike many other disabilities, difficult to detect.