The Instruments for Assessing Understanding and Appreciation of Miranda Rights were originally developed in the 1970s by Thomas Grisso as a research tool to inform public policy about juveniles' and adults' capacities to waive rights. The tool, composed of four distinct instruments, was subsequently adopted for use in juvenile and adult forensic evaluations, and the instruments were published for clinical use in 1998. A revised version of the instruments, the Miranda Rights Comprehension Instruments–II, has been developed and normed, and the manual is in preparation.