(a) Any law enforcement officer who, in the light of his observations, information and experience, has a reasonable belief that (i) a person may be wearing, carrying, or transporting a firearm in violation of section 454 of this title, (ii) by virtue of his possession of a firearm, such person is or may be presently dangerous to the officer or to others, (iii) it is impracticable, under the circumstances, to obtain a search warrant; and (iv) it is necessary for the officer's protection or the protection of others to take swift measures to discover whether such person is, in fact, wearing, carrying, or transporting a firearm, such officer may:
(1) approach the person and identify himself as a law enforcement officer;
(2) request the person's name and address, and, if the person is in a vehicle, his license to operate the vehicle, and the vehicle's registration; and
(3) ask such questions and request such explanations as may be reasonably calculated to determine whether the person is, in fact, unlawfully wearing, carrying, or transporting a firearm in violation of section 454 of this title; and
(4) if the person does not give an explanation which dispels, the reasonable belief which he had, he may conduct a search of the person, limited to a patting or frisking of the person's clothing in search of a firearm. The police officer in acting under this section shall do so with due regard to all circumstances of the occasion, including but not limited to the age, appearance, physical condition, manner and sex of the person approached.
(b) In the event that the officer discovers the person to be wearing, carrying, or transporting a firearm, he may demand that the person produce evidence that he is entitled to so wear, carry, or transport the firearm pursuant to section 454 of this title. If the person is unable to produce such evidence, the officer may then seize the firearm and arrest the person.
(c) Nothing in this section shall be construed to limit the right of any police officer to make any other type of search, seizure, and arrest which may be permitted by law.