On the first day of January next following the appointment in any county of the first members of the law enforcement agency under the provisions of this act and thereafter, the law enforcement department shall assume and shall exercise all powers, duties and responsibilities previously exercised by the sheriff, deputies of the sheriff and constables. The sheriff, upon demand, shall transfer and deliver to the agency all vehicles, property and records belonging to the sheriff’s department. A record of all property so transferred shall be prepared and copies thereof filed in the office of the county clerk and with the secretary of the agency. On the date fixed for the transfer of such authority, any person serving as a full-time deputy of the sheriff of the county on such date, holding a law enforcement training certificate and meeting the qualifications established by the county law enforcement agency, may become a member of the department.