Mental Illness and Criminal Justice

Mood and Psychotic Disorders

Mental Illness and Criminal JusticeThe October 2013 ABA Journal reported a history of mental illness among 61% of premeditated murderers.

Based on research by Robert Hanlon, however, 34% of impulsive murderers have a history of mood and psychotic disorders.

Therefore, these disorders were twice as common among premeditated murderers as compared to impulsive murderers.

Mental Illness: Cognitive and Intellectual Impairments

Hanlon’s research shows 59% of impulsive murderers are developmentally disabled with cognitive and intellectual impairments. By comparison, 36% of premeditated murderers have this history. Therefore, a history of cognitive and intellectual impairment appeared about twice as often among impulsive murderers as compared to premeditated murderers.

Substance Abuse

The research shows 93% of impulsive murderers have a history of alcohol or drug abuse, were intoxicated, or both, at the time of their crime. By comparison, 76% of premeditated murderers met these criteria. Therefore, impulsive murderers were more likely than premeditated murderers to have a history of substance abuse, or were actually under the influence of a substance, at the time of their crime.


This research does not reflect the percentage of all people with these histories. It reflects the percentage of people who have committed these crimes with these histories. It follows, of course, that a percentage of those who committed homicide did not have these histories. Therefore, these histories are neither sufficient nor necessary to predict who will commit homicide.

For additional Gavel Report coverage of mental illness, please click here (Elyn Saks: A Tale of Mental Illness—From The Inside), and here (Ruby Wax: What’s So Funny About Mental Illness?).

Michael A. Smolensky, Esq., knows how to protect his clients. Mr. Smolensky can provide consultations on all cases regarding . Call Now—(856) 812-0321.