It shall be unlawful for a parent having legal custody of a minor knowingly to permit or, by inefficient control, to allow the minor to be or remain upon any city street under circumstances not constituting an exception to, or otherwise beyond the scope of, this chapter. The term "knowingly" includes knowledge which a parent should reasonably be expected to have concerning the whereabouts of a minor in that parent's legal custody. It shall be no defense that a parent was completely indifferent to the activities or conduct or whereabouts of the minor. (2001 Code § 136.06)