It shall be unlawful for any person to loiter, as hereinafter defined, in, on, or about any place, public or private, when such loitering is accompanied by activity or is under circumstances that afford probable cause for alarm or concern for the safety and well-being of persons or for the security of property, in the surrounding area.
(1995 Code of Ordinances, Chapter 7, Article 7.500, Section 7.501)
(a) 
For the purposes of this article, the term "loiter" shall include the following activities: The walking about aimlessly without apparent purpose; lingering; hanging around; lagging behind; and moving slowly about, where such conduct is not due to physical defects or conditions.
(b) 
For the purposes of this article, the term "any place," public or private, shall include, but not be limited to, the following: All places commonly known as being distinctively public, such as public streets, public restrooms, sidewalks, parks, municipal airports, alleys and buildings; all places privately owned but open to the public generally such as shopping centers, transportation terminals, retail stores, movie theaters, office buildings, and restaurants; and, all places distinctively private, such as homes or private residences and apartment houses.
(c) 
For the purposes of this article, the term "surrounding area" shall be defined as follows: That area easily and immediately accessible to the person under observation.
(1995 Code of Ordinances, Chapter 7, Article 7.500, Section 7.502)
Without limitation, the following activities and circumstances may be considered in determining probable cause for alarm or concern:
(1) 
The flight of a person upon the appearance of a peace officer or any other person;
(2) 
Attempted concealment by a person upon the appearance of a peace officer or any other person;
(3) 
The systematic checking by a person of doors, windows, or other means of access to buildings, houses, or vehicles;
(4) 
Repeated activity by a person, continuous or broken, which outwardly manifests no purpose, such as going from one place to another and back with no showing of use for such movement;
(5) 
Continuous presence by a person in close proximity to any building, house, vehicle, or any other property or to any other person, at any time when the activity of such person manifests possible unlawful activity, such continuous presence being for an unreasonable period of time under the circumstances then existing;
(6) 
A change of direction by a person upon the appearance of a peace officer in order to avoid meeting or crossing paths of such officer;
(7) 
If on private property, the continued refusal of a person to leave such private property when requested to do so by the owner, manager, proprietor, or lessee of such property.
(1995 Code of Ordinances, Chapter 7, Article 7.500, Section 7.503)