Many, if not most, of the people with mental retardation convicted of capital murder are doubly and triply disadvantaged. In general, America’s prison population is made up disproportionately of poor people, minorities, the mentally ill, and those who were abused as children. Not surprisingly, the mentally retarded people who become enmeshed in the criminal justice system usually share one or more of these characteristics: many of them come from poor families, suffered from severe abuse as children, and/or face mental illness in addition to their retardation.
A history of severe childhood abuse is particularly common among defendants with mental retardation convicted of capital murder. While the relationship between abuse and adult behavior is complex, "Strong evidence exists that a person who was abused as a child is at risk of suffering long-term effects that may contribute to his violent behavior as an adult," particularly if the abuse was severe physical abuse that caused serious injury to the child. The long-term negative effects of childhood abuse may be even greater for people whose cognitive abilities are impaired and whose ability to navigate in the world is already seriously compromised by mental retardation.
Luis Mata was executed in Arizona in 1996, convicted of rape and murder. Mata suffered organic brain damage from multiple medical traumas and had an I.Q. tested variously between 63 and 70. Mata's alcoholic father beat all of his sixteen children, but he picked primarily on Luis, subjecting him to constant physical abuse--kicking him, punching him, and beating him with electrical cords. When Luis Mata was six, he fall off a truck, badly fracturing his skull, but his family was too poor to obtain medical treatment for him. This and other medical traumas may have contribute to his neurological deficits.
Freddie Lee Hall, with an I.Q. of 60, is on death row in Florida, convicted of killing a young pregnant woman, Hall was one of seventeen children in an impoverished family. As a child, he was "tortured by his mother, sometimes stuffed in a sack and swung over a fire, or tied to the rafters and beaten." His mother even encouraged neighbors to beat her son, and she buried him in the ground as a "cure" for his asthma.
Robert Anthony Carter, who had mental retardation, was convicted of a murder committed when he was seventeen and was executed in 1998. One of sic children, Carter was abused by both his mother and stepfather, who whipped and beat him with belts and cords. Carter's siblings would be forced to hold him down while his mother beat him. At other times, his mother would wait until Carter was asleep and then begin to whip him. He also suffered from several serious head injuries as a child - including one in which he was hit so hard with a baseball bat on the head that the bat broke.
Many capital defendants with mental retardation also suffer from mental illness. Although the two conditions are often confused, they are different disorders. Mental illness almost always includes disturbance of some sort in emotional life; intellectual functioning may be intact, except where thinking breaks with reality (as in hallucinations). A person who is mentally ill, e.g. who is bipolar or suffers from schizophrenia, can have a very high I.Q., while mentally retarded person always has a low I.Q. A person who is mentally ill, e.g. who is bipolar or suffers from schizophrenia, can have a very high I.Q., while a mentally retarded person always has a low I.Q. A person who is mentally ill may improve or be cured with therapy or medication, but mental retardation is a permanent state. Finally, mental illness may develop during any stage of life, while mental retardation is manifest by the age of eighteen. The percentage of mentally retarded people who are also mentally ill is not known with any certainty; estimates vary from 10 percent to 40 percent. Persons who suffer from both mental illness and mental retardation are particularly disadvantaged in dealing with the criminal justice system because each condition can compound the effects of the other.
Nollie Lee Martin had an I.Q. of 59 and was further mentally impaired as a result of several serious head injuries he had received in childhood. As a child he was physically and sexually abused and came from a family with a history of schizophrenia. His mental history included psychosis, suicidal depression, paranoid delusions, and self-mutilation. After being convicted in 1978 of kidnapping, robbery, and murder in Florida, Martin spent more than thirteen years on death row mostly incoherent and rocking back and forth on the floor of his cell. He required constant medication for his mental illness and hallucinations. He beat his head and fists against the cell wall and would mutilate himself. He was executed in 1992.
Emile Duhamel was convicted of the aggravated sexual assault and murder of a nine-year-old girl in 1984. He had an I.Q. of 56 and organic brain disease and suffered as well from paranoid schizophrenia and dementia. After a decade of legal proceedings over his competency for execution, Duhamel died in his Texas death row cell in 1998.
For the most part, statutes prohibiting the execution of persons with mental retardation adopt a version of this AAMR definition Seven States and the federal government do not specify an I.Q. level in their definition, making this an issue for the court to determine based on expert testimony. Two state statutes say that an I.Q. of 70 or below "shall be presumptive evidence of mental retardation," thus leaving open the possibility that a person whose I.Q. is above 70 may also, through expert testimony, estabilish his or her mental retardation.
The intellectual capacity of children was historically the benchmark for assessing the extent of retardation. In 1910, the American Association on Mental Deficiency identifies the three "levels of impairment" characterizing the "feebleminded”: there were "idiots", people "whose development is arrested at the level of a 2 year old";imbeciles," people whose development is equivalent to that of a 2 to 7 year old at maturity"; and morons," people "whose mental development is equivalent to that of a 7 to 12 year old at maturity." Fred J. Biasini, et al., The terminology entered common discourse as epithets reflecting the country's shameful history of prejudice and mistreatment of people with mental retardation. The punitive, exclusionary, and racist historical manipulation of the concept of "mental retardation" are addressed in Robert Perske, Deadly Innocence?
With the upper ceiling on mental retardation reduced from an I.Q. of 85 to an I.Q. of 70, far fewer Americans are today diagnosed as "mentally retarded" than before. Although the lower I.Q. ceiling for mental retardation was agreed upon in part to avoid applying stigmatizing labels to so many people whose intelligence was below average, the changed I.Q. ceiling ironically had the effect of cutting from social services such as special education many people who would have otherwise benefited from the extra support. Scholars have emphasized that because of the possibilities of testing error, a person with an I.Q. of up to 75 should be considered "retarded" if the diagnoses is necessary to ensure access to special education or other assistance.
