In recent years, the courts have occasionally questioned the mental competency of repeat offenders with kleptomania. In such cases, essentially lawyers, rather than psychiatrists, take the lead role in determining the individual's mental competency. However, the most important evidence that lawyers can obtain is from psychiatrists, who can evaluate the accused and provide expert opinion in court. Here, mental competency in cases of kleptomania is discussed from the viewpoint of forensic psychiatry. First, the author points out that the concept itself is an ideal type and then presents a typical case of kleptomania based on the diagnostic criteria of kleptomania in DSM-5. The scope of kleptomania is shown to be wider in medical practice than in legal practice and therefore the diagnostic criteria of kleptomania should be applied more rigorously in the courts in cases of habitual theft. The author concludes by discussing judicial judgements of mental competency and extenuation in cases of kleptomania.
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