PT - JOURNAL ARTICLE AU - Slovenko, Ralph TI - Commentary: Deceptions to the Rule on Ultimate Issue Testimony DP - 2006 Jan 01 TA - Journal of the American Academy of Psychiatry and the Law Online PG - 22--25 VI - 34 IP - 1 4099 - http://jaapl.org/content/34/1/22.short 4100 - http://jaapl.org/content/34/1/22.full SO - J Am Acad Psychiatry Law2006 Jan 01; 34 AB - Federal Rule of Evidence 704(b) (and state counterparts) bars opinion testimony on the effect of mental state on an element of a crime or defense. The application of the rule involves substantial judicial discretion. As the jurisprudence to date indicates, deceptions to the rule circumvent its application.