If, after investigating the applicant, the Chief of Police determines that the applicant for a permit required by this chapter is qualified as a law abiding person, has good credit standing and a verifiable employment history and proposes to engage in a lawful commercial or professional enterprise during hours that will not unduly disturb the occupants of residences, the Chief of Police shall issue to him or her a permit to engage in the business, which permit shall contain substantially the information set forth in his or her application and to which shall be attached his or her photograph and fingerprints. The permit shall be carried at all times by the person to whom issued when soliciting or canvassing in the city and shall be exhibited by him or her whenever required to do so by any police officer or any person solicited. If the Chief of Police, upon investigation, determines that the applicant is not qualified as herein provided and does not propose to engage in a lawful commercial or professional enterprise during hours reasonably convenient for the occupants of residences, he or she shall refuse to issue the permit.