Md. Code, Business Occupations and Professions § 13–701

(a) A person may not engage in, attempt to engage in, offer to engage in, or solicit to engage in a business for the purpose of providing private detective services in the State unless licensed as a private detective agency by the Secretary.

(b) An individual may not provide, attempt to provide, offer to provide, or solicit to provide private detective services in the State unless certified as a private detective by the Secretary.