In making recommendations for best practice, this online resource helps readers to consider empirical support, legal relevance, and consistency with ethical and professional standards. It offers invaluable guidance for anyone involved in conducting or using forensic evaluations. Patients provide valid informed consent to a treatment or a diagnostic procedure if they have sufficient capacity, have been given appropriate information, and give consent freely without coercion or undue influence. When a patient's capacity for treatment consent is in doubt, a clinician must determine whether the patient indeed has the capacity. This resource provides clear, step-by-step information on the evaluation procedure for capacity to consent to both treatment and research.