Tex. Family Code § 51.20

(a) At any stage of the proceedings under this title, including when a child is initially detained in a pre-adjudication secure detention facility or a post-adjudication secure correctional facility, the juvenile court may, at its discretion or at the request of the child's parent or guardian, order a child who is referred to the juvenile court or who is alleged by a petition or found to have engaged in delinquent conduct or conduct indicating a need for supervision to be examined by a disinterested expert, including a physician, psychiatrist, or psychologist, qualified by education and clinical training in mental health or intellectual disability and experienced in forensic evaluation, to determine whether the child has a mental illness as defined by Section 571.003, Health and Safety Code, is a person with an intellectual disability as defined by Section 591.003, Health and Safety Code, or suffers from chemical dependency as defined by Section 464.001, Health and Safety Code.

(b) If, after conducting an examination of a child ordered under Subsection (a) and reviewing any other relevant information, there is reason to believe that the child has a mental illness or intellectual disability or suffers from chemical dependency, the probation department shall refer the child to the local mental health authority, to the local intellectual and developmental disability authority, or to another appropriate and legally authorized agency or provider for evaluation and services, unless the prosecuting attorney has filed a petition under Section 53.04.

(c) If, while a child is under deferred prosecution supervision or court-ordered probation, a qualified professional determines that the child has a mental illness or intellectual disability or suffers from chemical dependency and the child is not currently receiving treatment services for the mental illness, intellectual disability, or chemical dependency, the probation department shall refer the child to the local mental health authority, to the local intellectual and developmental disability authority, or to another appropriate and legally authorized agency or provider for evaluation and services.

(d) A probation department shall report each referral of a child to a local mental health authority, to a local intellectual and developmental disability authority, or to another agency or provider made under Subsection (b) or (c) to the Texas Juvenile Justice Department in a format specified by the department.

(e) At any stage of the proceedings under this title, the juvenile court may order a child who has been referred to the juvenile court or who is alleged by the petition or found to have engaged in delinquent conduct or conduct indicating a need for supervision to be subjected to a physical examination by a licensed physician.