Under what conditions can a defendant be considered "insane" in a Texas court?

The correct understanding of how a defendant can be considered "insane" in a Texas court is closely tied to the legal definition of insanity, particularly as outlined in the Texas Penal Code. Under Texas law, a defendant may be considered legally insane if, at the time of the conduct charged, they did not have substantial capacity to appreciate the criminality of their conduct, or did not have the ability to conform their conduct to the requirements of the law. This translates to the criteria that they either did not understand the nature and quality of their actions or did not know they were wrong.

This definition highlights the focus on the defendant's cognitive and moral understanding at the time of the offense rather than their emotional state or psychological history. This is distinctly separate from conditions influenced by extreme stress, prior mental illness, or substance use, all of which may impact a defendant’s behavior but do not directly align with the legal definition of insanity under Texas law. Thus, the stipulation of not understanding the nature and quality of their actions or knowing that their actions were wrong is what is essential for establishing a defense based on insanity in Texas courts.