Cal. Welf. & Inst. Code § 324.5
(a) Whenever allegations of physical or sexual abuse of a child come to the attention of a local law enforcement agency or the local child welfare department and the child is taken into protective custody, the local law enforcement agency, or child welfare department may, as soon as practically possible, consult with a medical practitioner, who has specialized training in detecting and treating child abuse injuries and neglect, to determine whether a physical examination of the child is appropriate. If deemed appropriate, the local law enforcement agency, or the child welfare department, shall cause the child to undergo a physical examination performed by a medical practitioner who has specialized training in detecting and treating child abuse injuries and neglect, and, whenever possible, shall ensure that this examination take place within 72 hours of the time the child was taken into protective custody. In the event the allegations are made while the child is in custody, the physical examination shall be performed within 72 hours of the time the allegations were made.
In the case of a petition filed pursuant to Section 319, the department shall provide the results of the physical examination to the court and to any counsel for the minor, and counsel for the parent or guardian of the minor. Failure to obtain this physical examination shall not be grounds to deny a petition under this section.