law: 136. Officers holding charges of, or succeeding to, vacancies competent to exercise powers.-
  Whenever in consequence of the office of the Commissioner of Police, Additional Commissioner of Police or any police officer becoming vacant, any officer holds charge of the post of such Commissioner of Police, Additional Commissioner of Police or other police officer or succeeds, either temporarily or permanently, to that post, such officer shall be competent to exercise all the powers and perform all the duties respectively conferred and imposed by or under this Act on the Commissioner of Police or on such Additional Commissioner of Police or other police officer, as the case may be.