Guilty but Mentally Ill

The guilty but mentally ill (GBMI) verdict is a verdict option that enables juries and judges to find a defendant guilty of committing an offense while formally acknowledging that the defendant has a mental illness. The GBMI does not usually replace the insanity defense standard but presents an additional verdict option. The GBMI verdict has met with sound criticism and little empirical support; nonetheless, 20 states have adopted it.

Although the idea of holding mentally ill people “guilty” for their criminal acts has been brewing for some time, the single event that brought the guilty but mentally ill verdict to fruition may have been the Michigan Supreme Court’s decision in People v. McQuillan (1974). In this case, the court held that it is unconstitutional to detain people who have been found not guilty by reason of insanity (NGRI) for indefinite periods, insofar as it violates their due process and equal protection rights. After some crimes were committed by those found NGRI and later released, the Michigan Legislature passed a law in 1982 introducing a new verdict—GBMI.

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A defendant who receives a GBMI verdict is sentenced in the same way as if he or she were found guilty. The court then determines whether and to what extent the defendant requires treatment for mental illness. When, and if, the defendant’s mental illness is deemed to have been stabilized, the offender is required to serve out the rest of his or her sentence. This is different from the case of individuals who have been found NGRI. In those cases, the insanity-defense acquittee is released from psychiatric commitment once he or she is deemed to be no longer dangerous.

Essentially, the GBMI verdict holds defendants criminally responsible for their acts but recognizes that the defendant is mentally ill. The GBMI verdict is typically employed as an option in addition to the NGRI and guilty verdicts, leaving it to the jury to decide, for example, if the defendant should be found guilty, not guilty, NGRI, or GBMI. The rationale for introducing the GBMI option was to reduce the number of insanity acquittals in Michigan and to prevent the early release of NGRI acquittees, which legislators feared would occur following the McQuillan case. The GBMI plea has been termed an “in-between classification,” since defendants are neither acquitted nor found guilty in the traditional sense.

The introduction of the GBMI verdict has produced a rather tumultuous controversy. Proponents of the GBMI verdict assert that it provides for necessary treatment of mentally ill defendants while still ensuring that those defendants are punished for their crimes. Other supporters argue that the GBMI verdict protects the public because mentally ill defendants serve the remainder of their sentence in prison after they are well, which would not happen with defendants found not guilty by reason of insanity.

Some commentators argue that the verdict has been successful because it allows defendants to be held criminally responsible for their actions while also enabling them to seek treatment. In sharp contrast to these benefits, critics argue that the GBMI verdict is simply an overreaction to a problem that really does not exist—that is, that the insanity defense does not allow dangerous defendants to simply “get off.” Moreover, research has not shown a reduction in the use of the insanity defense in states where the GBMI verdict has been introduced.

Similarly, critics argue that the GBMI verdict serves no necessary purpose and is a misleading verdict, introduced because of purely political reasons. It is argued that the verdict only confuses jurors and enables them to find a disproportionate number of defendants “guilty.” Indeed, some mock jury research has found that mock jurors tend to use the GBMI verdict as a “compromise” verdict where members of the jury are torn between finding a defendant guilty or finding the defendant NGRI.

Perhaps the most significant criticism of the GBMI verdict is that the jury, when instructed about their verdict options, are not informed about the consequences of a finding of GBMI. Given the dearth of treatment services available for people in prisons with mental illnesses and the disproportionate number of prisoners who suffer from a mental illness, the reality is that many people with mental illnesses do not receive the treatment they require when they are in prison—regardless of whether they have been found GBMI or not.

Despite the criticisms of the GBMI verdict and the general lack of support for it, the verdict has proven quite popular with politicians. Since its inception 25 years ago, at least 20 states have enacted GBMI provisions.


  1. Blunt, L. W., & Stock, H. (1985). Guilty but mentally ill: An alternative verdict. Behavioral Sciences and the Law, 8, 49-67.
  2. Melville, J. D., & Naimark, D. (2002). Punishing the insane: The verdict of guilty but mentally ill. Journal of the American Academy of Psychiatry and Law, 30, 553-555.
  3. People v. McQuillan, 392 Mich. 511, 221 N.W.2d 569 (1974).

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