Mental Illness - As introduced, establishes a rebuttable presumption that a person poses an imminent substantial likelihood of serious harm and needs emergency detention and examination if the person was charged with one of certain criminal offenses and ordered by the criminal, circuit, or general sessions court to undergo an evaluation to determine whether the person is incompetent to stand trial or the person's mental capacity at the time of the commission of the crime; requires clear and convincing evidence to rebut the presumption. - Amends TCA Title 33; Title 40 and Title 52.

SB 662 creates a legal presumption that defendants charged with specific serious crimes must undergo emergency mental health evaluations if a court has already ordered such evaluations to assess competency or mental state at the time of the crime. It applies to offenses where, if convicted, the person would serve at least 85% of their sentence before release eligibility. The presumption can only be overturned with "clear and convincing evidence" that the person does not pose an imminent substantial risk of serious harm. This bill modifies Tennessee's mental health evaluation procedures under Titles 33, 40, and 52 of state law.