Stephen Ruffin, Appellant v. the State of Texas

Summary

The Court held that lay and expert testimony of a defendant’s mental disease or defect that directly rebuts the mens rea element of aggravated assault is admissible unless excluded by a specific evidentiary rule. It reversed the Court of Appeals’ judgment that barred such evidence because the case did not involve homicide or an insanity defense, and remanded for further proceedings consistent with this holding.